diff --git a/docs/discord.md b/docs/discord.md
index ad3d2f3983..f8a37cdb58 100644
--- a/docs/discord.md
+++ b/docs/discord.md
@@ -51,6 +51,24 @@ Your character's name is never shown, in any setting.
 
 The setting applies immediately and is stored in `config.ini`.
 
+## Messages from Discord
+
+> Requires a server with a Discord chat bridge, like OpenMU's (its guild and
+> alliance chat can be bound to Discord channels).
+
+A message written in a Discord channel that the server bridges into the game
+appears in the chat of its scope - guild or alliance - with that chat's
+colours. Its sender is shown as `[Discord] <name>`: with OpenMU's bridge the
+name is the character the Discord user is linked to (OpenMU sends it as
+`@<name>`, which no character can be called). A server that sends the Discord
+name itself can show it with up to 32 characters.
+
+- Discord users are not characters: right-clicking their line does not start a
+  whisper, and they are not added to your whisper list.
+- **F2** switches the chat log between all messages and whispers. Once a
+  message from Discord has arrived, it also offers a view with only the
+  messages from Discord: all → whispers → Discord → all.
+
 ## For server operators
 
 Each server uses its own Discord application, so the name your players see
diff --git a/src/source/Network/Server/WSclient.cpp b/src/source/Network/Server/WSclient.cpp
index 7932fbbc42..763c87466f 100644
--- a/src/source/Network/Server/WSclient.cpp
+++ b/src/source/Network/Server/WSclient.cpp
@@ -1,6 +1,7 @@
 #include "stdafx.h"
 #include "App/Control/ControlTaps.h"
 #include "Core/Utilities/Log/MuLogger.h"
+#include "UI/Chat/ExternalChat.h"
 #include "UI/Chat/Chat.h"
 #include "UI/Chat/ChatMessages.h"
 #include "UI/Combat/SiegeUpdates.h"
@@ -1819,12 +1820,23 @@ void ReceiveChat(const BYTE* ReceiveBuffer)
         {
             for (int i = 0; i < messageSize - 2; i++)
                 Text[i] = Text[i + 2];
+            if (UI::Chat::External::IsBridgedSender(ID))
+            {
+                // Recorded for the control socket as a Discord line instead.
+                UI::Chat::External::ShowBridged(UI::Chat::External::Scope::Alliance, ID, Text);
+                return;
+            }
             UI::Chat::PostChat(ID, Text, mu::ui::window::TYPE_UNION_MESSAGE);
         }
         else if (Text[0] == L'@')
         {
             for (int i = 0; i < messageSize - 1; i++)
                 Text[i] = Text[i + 1];
+            if (UI::Chat::External::IsBridgedSender(ID))
+            {
+                UI::Chat::External::ShowBridged(UI::Chat::External::Scope::Guild, ID, Text);
+                return;
+            }
             UI::Chat::PostChat(ID, Text, mu::ui::window::TYPE_GUILD_MESSAGE);
         }
         else if (Text[0] == L'$')
diff --git a/src/source/UI/Chat/ExternalChat.cpp b/src/source/UI/Chat/ExternalChat.cpp
new file mode 100644
index 0000000000..40195a2b85
--- /dev/null
+++ b/src/source/UI/Chat/ExternalChat.cpp
@@ -0,0 +1,74 @@
+#include "stdafx.h"
+#include "UI/Chat/ExternalChat.h"
+
+#include "App/Control/ControlTaps.h"
+#include "Network/Server/WSclient.h"
+#include "UI/Core/WindowSystem.h"
+
+namespace
+{
+constexpr const wchar_t* DiscordBadge = L"[Discord] ";
+constexpr const char* DiscordChatKind = "discord";
+} // namespace
+
+namespace UI::Chat::External
+{
+std::wstring SenderLabel(Source source, std::wstring_view displayName)
+{
+    switch (source)
+    {
+    case Source::Discord:
+    default:
+        return DiscordBadge + std::wstring(displayName.substr(0, MaxDisplayNameLength));
+    }
+}
+
+mu::ui::window::MESSAGE_TYPE ScopeMessageType(Scope scope)
+{
+    switch (scope)
+    {
+    case Scope::Guild:
+        return mu::ui::window::TYPE_GUILD_MESSAGE;
+    case Scope::Alliance:
+        return mu::ui::window::TYPE_UNION_MESSAGE;
+    case Scope::World:
+    default:
+        return mu::ui::window::TYPE_CHAT_MESSAGE;
+    }
+}
+
+std::wstring ShownText(std::wstring_view text)
+{
+    return std::wstring(text.substr(0, MAX_CHAT_SIZE));
+}
+
+// Unlike an in-game message, no speech balloon (nobody stands there) and no
+// entry in the whisper allow-list (nobody to whisper).
+void Show(const Message& message)
+{
+    const std::wstring sender = SenderLabel(message.source, message.displayName);
+    const std::wstring text = ShownText(message.text);
+    if (text.empty())
+    {
+        return;
+    }
+
+    g_pChatListBox->AddExternalText(sender, text, ScopeMessageType(message.scope));
+    App::Control::Events::RecordChatLine(sender.c_str(), text.c_str(), DiscordChatKind);
+}
+
+bool IsBridgedSender(std::wstring_view sender)
+{
+    return sender.size() > 1 && sender.front() == BridgedSenderPrefix;
+}
+
+void ShowBridged(Scope scope, std::wstring_view sender, std::wstring_view text)
+{
+    Message message;
+    message.source = Source::Discord;
+    message.scope = scope;
+    message.displayName = std::wstring(sender.substr(1));
+    message.text = std::wstring(text);
+    Show(message);
+}
+} // namespace UI::Chat::External
diff --git a/src/source/UI/Chat/ExternalChat.h b/src/source/UI/Chat/ExternalChat.h
new file mode 100644
index 0000000000..6657ac85d2
--- /dev/null
+++ b/src/source/UI/Chat/ExternalChat.h
@@ -0,0 +1,70 @@
+// Chat messages written outside the game - today in a Discord channel that
+// the server bridges into guild, alliance or world chat (#700).
+//
+// They are shown as such: the sender is marked with where they wrote, keeps
+// a name longer than a character's, and can't be whispered, because there
+// is no character behind it.
+#pragma once
+
+#include "UI/HUD/ChatLogWindow.h"
+
+#include <cstddef>
+#include <string>
+#include <string_view>
+
+namespace UI::Chat::External
+{
+enum class Source
+{
+    Discord,
+};
+
+// Which in-game chat the message belongs to; it takes that chat's colours.
+enum class Scope
+{
+    Guild,
+    Alliance,
+    World,
+};
+
+// Discord's display names are at most 32 characters long.
+inline constexpr std::size_t MaxDisplayNameLength = 32;
+
+struct Message
+{
+    Source source = Source::Discord;
+    Scope scope = Scope::World;
+    std::wstring displayName;
+    std::wstring text;
+};
+
+// What the chat log shows as the sender: "[Discord] name", the name cut to
+// MaxDisplayNameLength characters.
+[[nodiscard]] std::wstring SenderLabel(Source source, std::wstring_view displayName);
+
+// The chat log type whose colours the scope uses.
+[[nodiscard]] mu::ui::window::MESSAGE_TYPE ScopeMessageType(Scope scope);
+
+// The text as shown: cut to the length of an in-game chat message.
+[[nodiscard]] std::wstring ShownText(std::wstring_view text);
+
+// Shows the message in the chat log, in its scope and in the Discord view.
+void Show(const Message& message);
+
+// OpenMU's chat bridge (MUnique/OpenMU#1161) sends messages written in Discord
+// through the ordinary guild and alliance chat, as the linked character with
+// this prefix, which OpenMU doesn't allow in character names.
+//
+// This is a best-effort fallback for servers which don't send the dedicated
+// ExternalChatMessage: the prefix is a convention of the server, not a
+// guarantee the client can check - a server which allows it in character
+// names would have such characters shown as Discord users. When a server
+// sends ExternalChatMessage, that is the authoritative signal.
+inline constexpr wchar_t BridgedSenderPrefix = L'@';
+
+[[nodiscard]] bool IsBridgedSender(std::wstring_view sender);
+
+// Shows a guild or alliance chat line of a bridged sender as a message from
+// Discord, named after the character without the prefix.
+void ShowBridged(Scope scope, std::wstring_view sender, std::wstring_view text);
+} // namespace UI::Chat::External
diff --git a/src/source/UI/Chat/MessageType.h b/src/source/UI/Chat/MessageType.h
index 08bdfad4fc..230c4904fc 100644
--- a/src/source/UI/Chat/MessageType.h
+++ b/src/source/UI/Chat/MessageType.h
@@ -14,6 +14,9 @@ enum MESSAGE_TYPE
     TYPE_UNION_MESSAGE,
     TYPE_GENS_MESSAGE,
     TYPE_GM_MESSAGE,
+    // A view, not a message type: the messages from Discord. Each of them
+    // keeps the type of its scope (guild, alliance, chat) for its colours.
+    TYPE_DISCORD_MESSAGE,
 
     NUMBER_OF_TYPES,
     TYPE_UNKNOWN = 0xFFFFFFFF
diff --git a/src/source/UI/HUD/ChatInputBox.cpp b/src/source/UI/HUD/ChatInputBox.cpp
index 5305389e19..392b80a347 100644
--- a/src/source/UI/HUD/ChatInputBox.cpp
+++ b/src/source/UI/HUD/ChatInputBox.cpp
@@ -59,8 +59,6 @@ void mu::ui::window::CChatInputBox::Init()
     m_bShowSystemMessages = true;
     m_bShowChatLog = true;
     m_bWhisperSend = true;
-
-    m_bShowMessageElseNormal = false;
 }
 
 bool mu::ui::window::CChatInputBox::Create(
@@ -197,16 +195,7 @@ bool mu::ui::window::CChatInputBox::UpdateKeyEvent()
 {
     if (mu::ui::window::IsPress(VK_F2))
     {
-        m_bShowMessageElseNormal = !m_bShowMessageElseNormal;
-
-        if (m_bShowMessageElseNormal)
-        {
-            m_pNewUIChatLogWnd->ChangeMessage(mu::ui::window::TYPE_WHISPER_MESSAGE);
-        }
-        else
-        {
-            m_pNewUIChatLogWnd->ChangeMessage(mu::ui::window::TYPE_ALL_MESSAGE);
-        }
+        m_pNewUIChatLogWnd->ChangeMessage(m_pNewUIChatLogWnd->GetNextView());
 
         PlayBuffer(SOUND_CLICK01);
         return false;
diff --git a/src/source/UI/HUD/ChatInputBox.h b/src/source/UI/HUD/ChatInputBox.h
index 7ce6e74a9a..8821bc0968 100644
--- a/src/source/UI/HUD/ChatInputBox.h
+++ b/src/source/UI/HUD/ChatInputBox.h
@@ -80,7 +80,6 @@ namespace mu::ui::window
         bool m_bShowSystemMessages;
         bool m_bShowChatLog;
         bool m_bWhisperSend;
-        bool m_bShowMessageElseNormal;
 
         void Init();
 
diff --git a/src/source/UI/HUD/ChatLogWindow.cpp b/src/source/UI/HUD/ChatLogWindow.cpp
index 46a3886e84..e48f0bde1d 100644
--- a/src/source/UI/HUD/ChatLogWindow.cpp
+++ b/src/source/UI/HUD/ChatLogWindow.cpp
@@ -105,6 +105,18 @@ void mu::ui::window::CChatLogWindow::Release()
 }
 
 void mu::ui::window::CChatLogWindow::AddText(const type_string& strID, const type_string& strText, MESSAGE_TYPE MsgType, MESSAGE_TYPE ErrMsgType /*= TYPE_ALL_MESSAGE*/)
+{
+    AddTextToViews(strID, strText, MsgType, ErrMsgType, false);
+}
+
+void mu::ui::window::CChatLogWindow::AddExternalText(const type_string& strSender, const type_string& strText,
+                                                    MESSAGE_TYPE MsgType)
+{
+    AddTextToViews(strSender, strText, MsgType, TYPE_ALL_MESSAGE, true);
+}
+
+void mu::ui::window::CChatLogWindow::AddTextToViews(const type_string& strID, const type_string& strText,
+                                                   MESSAGE_TYPE MsgType, MESSAGE_TYPE ErrMsgType, bool bExternal)
 {
     if (strID.empty() && strText.empty())
     {
@@ -121,19 +133,24 @@ void mu::ui::window::CChatLogWindow::AddText(const type_string& strID, const typ
         RemoveFrontLine(TYPE_ALL_MESSAGE);
     }
 
+    if (bExternal && GetNumberOfLines(TYPE_DISCORD_MESSAGE) >= MAX_NUMBER_OF_LINES)
+    {
+        RemoveFrontLine(TYPE_DISCORD_MESSAGE);
+    }
+
     if (m_vecFilters.empty())
     {
-        ProcessAddText(strID, strText, MsgType, ErrMsgType);
+        ProcessAddText(strID, strText, MsgType, ErrMsgType, bExternal);
     }
     else
     {
         if (MsgType != TYPE_CHAT_MESSAGE)
         {
-            ProcessAddText(strID, strText, MsgType, ErrMsgType);
+            ProcessAddText(strID, strText, MsgType, ErrMsgType, bExternal);
         }
         else if (CheckFilterText(strID) || CheckFilterText(strText))
         {
-            ProcessAddText(strID, strText, MsgType, ErrMsgType);
+            ProcessAddText(strID, strText, MsgType, ErrMsgType, bExternal);
 
             if (g_pOption->IsWhisperSound())
             {
@@ -143,7 +160,45 @@ void mu::ui::window::CChatLogWindow::AddText(const type_string& strID, const typ
     }
 }
 
-void mu::ui::window::CChatLogWindow::ProcessAddText(const type_string& strID, const type_string& strText, MESSAGE_TYPE MsgType, MESSAGE_TYPE ErrMsgType)
+void mu::ui::window::CChatLogWindow::AppendMessage(type_vector_msgs* pvecMsgs, const type_string& strID,
+                                                  const type_string& strText, MESSAGE_TYPE MsgType, bool bExternal)
+{
+    const auto pMsgText = new CMessageText;
+    if (!pMsgText->Create(strID, strText, MsgType, bExternal))
+    {
+        delete pMsgText;
+        return;
+    }
+    pvecMsgs->push_back(pMsgText);
+}
+
+mu::ui::window::CChatLogWindow::type_vector_msgs*
+mu::ui::window::CChatLogWindow::GetSecondaryMsgs(MESSAGE_TYPE MsgType, MESSAGE_TYPE ErrMsgType, bool bExternal)
+{
+    if (bExternal)
+    {
+        return &m_vecDiscordMsgs;
+    }
+
+    // An error caused by, say, a whisper is listed among the whispers too.
+    if (MsgType == TYPE_ERROR_MESSAGE && ErrMsgType != TYPE_ERROR_MESSAGE && ErrMsgType != TYPE_ALL_MESSAGE)
+    {
+        type_vector_msgs* pErrvecMsgs = GetMsgs(ErrMsgType);
+        assert(pErrvecMsgs != nullptr && "Error chat");
+        return pErrvecMsgs;
+    }
+
+    return nullptr;
+}
+
+bool mu::ui::window::CChatLogWindow::IsInCurrentView(MESSAGE_TYPE MsgType, bool bExternal) const
+{
+    const MESSAGE_TYPE current = GetCurrentMsgType();
+    return current == TYPE_ALL_MESSAGE || current == MsgType || (bExternal && current == TYPE_DISCORD_MESSAGE);
+}
+
+void mu::ui::window::CChatLogWindow::ProcessAddText(const type_string& strID, const type_string& strText,
+                                                   MESSAGE_TYPE MsgType, MESSAGE_TYPE ErrMsgType, bool bExternal)
 {
     m_bLinesDirty = true;
     type_vector_msgs* pvecMsgs = GetMsgs(MsgType);
@@ -153,6 +208,8 @@ void mu::ui::window::CChatLogWindow::ProcessAddText(const type_string& strID, co
         return;
     }
 
+    type_vector_msgs* pSecondaryMsgs = GetSecondaryMsgs(MsgType, ErrMsgType, bExternal);
+
     int nScrollLines = 0;
     if (strText.size() >= 20)
     {
@@ -160,84 +217,28 @@ void mu::ui::window::CChatLogWindow::ProcessAddText(const type_string& strID, co
         SeparateText(strID, strText, MsgType, strText1, strText2);
         if (!strText1.empty())
         {
-            const auto pMsgText = new CMessageText;
-            if (!pMsgText->Create(strID, strText, MsgType))
-                delete pMsgText;
-            else
+            AppendMessage(pvecMsgs, strID, strText, MsgType, bExternal);
+            AppendMessage(&m_vecAllMsgs, strID, strText1, MsgType, bExternal);
+            if (pSecondaryMsgs != nullptr)
             {
-                pvecMsgs->push_back(pMsgText);
+                AppendMessage(pSecondaryMsgs, strID, strText1, MsgType, bExternal);
             }
 
-            const auto pAllMsgText = new CMessageText;
-            if (!pAllMsgText->Create(strID, strText1, MsgType))
-            {
-                delete pAllMsgText;
-            }
-            else
-            {
-                m_vecAllMsgs.push_back(pAllMsgText);
-            }
-
-            if ((MsgType == TYPE_ERROR_MESSAGE) && (ErrMsgType != TYPE_ERROR_MESSAGE && ErrMsgType != TYPE_ALL_MESSAGE))
-            {
-                type_vector_msgs* pErrvecMsgs = GetMsgs(ErrMsgType);
-                if (pErrvecMsgs == nullptr)
-                {
-                    assert(!"Error Chat");
-                    return;
-                }
-
-                const auto pErrMsgText = new CMessageText;
-                if (!pErrMsgText->Create(strID, strText1, MsgType))
-                    delete pErrMsgText;
-                else
-                {
-                    pErrvecMsgs->push_back(pErrMsgText);
-                }
-            }
-
-            if (GetCurrentMsgType() == TYPE_ALL_MESSAGE || GetCurrentMsgType() == MsgType)
+            if (IsInCurrentView(MsgType, bExternal))
             {
                 nScrollLines++;
             }
         }
         if (!strText2.empty())
         {
-            const auto pMsgText = new CMessageText;
-            if (!pMsgText->Create(L"", strText2, MsgType))
-                delete pMsgText;
-            else
+            AppendMessage(pvecMsgs, L"", strText2, MsgType, bExternal);
+            AppendMessage(&m_vecAllMsgs, L"", strText2, MsgType, bExternal);
+            if (pSecondaryMsgs != nullptr)
             {
-                pvecMsgs->push_back(pMsgText);
+                AppendMessage(pSecondaryMsgs, L"", strText2, MsgType, bExternal);
             }
 
-            const auto pAllMsgText = new CMessageText;
-            if (!pAllMsgText->Create(L"", strText2, MsgType))
-                delete pAllMsgText;
-            else
-            {
-                m_vecAllMsgs.push_back(pAllMsgText);
-            }
-
-            if ((MsgType == TYPE_ERROR_MESSAGE) && (ErrMsgType != TYPE_ERROR_MESSAGE && ErrMsgType != TYPE_ALL_MESSAGE))
-            {
-                type_vector_msgs* pErrvecMsgs = GetMsgs(ErrMsgType);
-                if (pErrvecMsgs == nullptr)
-                {
-                    assert(!"Error chat 2");
-                    return;
-                }
-
-                const auto pErrMsgText = new CMessageText;
-                if (!pErrMsgText->Create(L"", strText2, MsgType))
-                    delete pErrMsgText;
-                else
-                {
-                    pErrvecMsgs->push_back(pErrMsgText);
-                }
-            }
-
-            if (GetCurrentMsgType() == TYPE_ALL_MESSAGE || GetCurrentMsgType() == MsgType)
+            if (IsInCurrentView(MsgType, bExternal))
             {
                 nScrollLines++;
             }
@@ -245,42 +246,14 @@ void mu::ui::window::CChatLogWindow::ProcessAddText(const type_string& strID, co
     }
     else
     {
-        const auto pMsgText = new CMessageText;
-        if (!pMsgText->Create(strID, strText, MsgType))
-            delete pMsgText;
-        else
+        AppendMessage(pvecMsgs, strID, strText, MsgType, bExternal);
+        AppendMessage(&m_vecAllMsgs, strID, strText, MsgType, bExternal);
+        if (pSecondaryMsgs != nullptr)
         {
-            pvecMsgs->push_back(pMsgText);
+            AppendMessage(pSecondaryMsgs, strID, strText, MsgType, bExternal);
         }
 
-        const auto pAllMsgText = new CMessageText;
-        if (!pAllMsgText->Create(strID, strText, MsgType))
-            delete pAllMsgText;
-        else
-        {
-            m_vecAllMsgs.push_back(pAllMsgText);
-        }
-
-        if ((MsgType == TYPE_ERROR_MESSAGE)
-            && (ErrMsgType != TYPE_ERROR_MESSAGE && ErrMsgType != TYPE_ALL_MESSAGE))
-        {
-            type_vector_msgs* pErrvecMsgs = GetMsgs(ErrMsgType);
-            if (pErrvecMsgs == nullptr)
-            {
-                assert(!"Error chat 3");
-                return;
-            }
-
-            const auto pErrMsgText = new CMessageText;
-            if (!pErrMsgText->Create(strID, strText, MsgType))
-                delete pErrMsgText;
-            else
-            {
-                pErrvecMsgs->push_back(pErrMsgText);
-            }
-        }
-
-        if (GetCurrentMsgType() == TYPE_ALL_MESSAGE || GetCurrentMsgType() == MsgType)
+        if (IsInCurrentView(MsgType, bExternal))
         {
             nScrollLines++;
         }
@@ -856,8 +829,9 @@ void mu::ui::window::CChatLogWindow::UpdatePointedLine()
         type_vector_msgs* pvecMsgs = GetMsgs(GetCurrentMsgType());
         if (pvecMsgs != nullptr && pointed < (int)pvecMsgs->size())
         {
-            const type_string& strID = (*pvecMsgs)[pointed]->GetID();
-            if (!strID.empty() && g_pChatInputBox)
+            const CMessageText* pMsgText = (*pvecMsgs)[pointed];
+            const type_string& strID = pMsgText->GetID();
+            if (!strID.empty() && !pMsgText->IsExternal() && g_pChatInputBox)
                 g_pChatInputBox->SetWhsprID(strID.c_str());
         }
     }
@@ -1046,6 +1020,8 @@ mu::ui::window::CChatLogWindow::type_vector_msgs* mu::ui::window::CChatLogWindow
         return &m_vecGensMsgs;
     case TYPE_GM_MESSAGE:
         return &m_vecGMMsgs;
+    case TYPE_DISCORD_MESSAGE:
+        return &m_vecDiscordMsgs;
     }
 
     return nullptr;
@@ -1070,6 +1046,21 @@ mu::ui::window::MESSAGE_TYPE mu::ui::window::CChatLogWindow::GetCurrentMsgType()
     return m_CurrentRenderMsgType;
 }
 
+// Players on a server without a Discord chat bridge never get the Discord
+// view, so F2 keeps toggling between all messages and whispers for them.
+mu::ui::window::MESSAGE_TYPE mu::ui::window::CChatLogWindow::GetNextView() const
+{
+    switch (GetCurrentMsgType())
+    {
+    case TYPE_ALL_MESSAGE:
+        return TYPE_WHISPER_MESSAGE;
+    case TYPE_WHISPER_MESSAGE:
+        return m_vecDiscordMsgs.empty() ? TYPE_ALL_MESSAGE : TYPE_DISCORD_MESSAGE;
+    default:
+        return TYPE_ALL_MESSAGE;
+    }
+}
+
 void mu::ui::window::CChatLogWindow::ShowChatLog()
 {
     m_bShowChatLog = true;
diff --git a/src/source/UI/HUD/ChatLogWindow.h b/src/source/UI/HUD/ChatLogWindow.h
index 18deb1e157..151b2628da 100644
--- a/src/source/UI/HUD/ChatLogWindow.h
+++ b/src/source/UI/HUD/ChatLogWindow.h
@@ -31,12 +31,13 @@ namespace mu::ui::window
         type_string	m_strID, m_strText;
         MESSAGE_TYPE m_MsgType;
         DWORD m_dwIndentSize;
+        bool m_bExternal;
 
     public:
-        TMessageText() : m_MsgType(TYPE_UNKNOWN), m_dwIndentSize(0) {}
+        TMessageText() : m_MsgType(TYPE_UNKNOWN), m_dwIndentSize(0), m_bExternal(false) {}
         ~TMessageText() { Release(); }
 
-        bool Create(const type_string& strID, const type_string& strText, MESSAGE_TYPE MsgType)
+        bool Create(const type_string& strID, const type_string& strText, MESSAGE_TYPE MsgType, bool bExternal = false)
         {
             if (MsgType >= NUMBER_OF_TYPES)
                 return false;
@@ -44,6 +45,7 @@ namespace mu::ui::window
             m_strID = strID;
             m_strText = strText;
             m_MsgType = MsgType;
+            m_bExternal = bExternal;
 
             return true;
         }
@@ -52,11 +54,18 @@ namespace mu::ui::window
             m_strID.resize(0);
             m_strText.resize(0);
             m_MsgType = TYPE_UNKNOWN;
+            m_bExternal = false;
         }
 
         const type_string& GetID() const { return m_strID; }
         const type_string& GetText() const { return m_strText; }
         MESSAGE_TYPE GetType() const { return m_MsgType; }
+        // Written outside the game (in Discord): its sender is no character,
+        // so it can't be whispered.
+        bool IsExternal() const
+        {
+            return m_bExternal;
+        }
     };
 
     typedef TMessageText<wchar_t> CMessageText;
@@ -138,6 +147,7 @@ namespace mu::ui::window
         type_vector_msgs	m_VecSystemMsgs;
         type_vector_msgs	m_vecErrorMsgs;
         type_vector_msgs	m_vecGMMsgs;
+        type_vector_msgs m_vecDiscordMsgs;
         type_vector_filters	m_vecFilters;
 
         SIZE	m_WndSize;
@@ -209,6 +219,9 @@ namespace mu::ui::window
         void Release();
 
         void AddText(const type_string& strID, const type_string& strText, MESSAGE_TYPE MsgType, MESSAGE_TYPE ErrMsgType = TYPE_ALL_MESSAGE);
+        // A message written outside the game, in the given scope's type. It is
+        // also listed in the TYPE_DISCORD_MESSAGE view.
+        void AddExternalText(const type_string& strSender, const type_string& strText, MESSAGE_TYPE MsgType);
         void RemoveFrontLine(MESSAGE_TYPE MsgType);
         void Clear(MESSAGE_TYPE MsgType);
         void ClearAll();
@@ -217,6 +230,9 @@ namespace mu::ui::window
         MESSAGE_TYPE GetCurrentMsgType() const;
 
         void ChangeMessage(MESSAGE_TYPE MsgType);
+        // The view F2 switches to from the current one: all, whispers, and
+        // Discord once a message from Discord has arrived.
+        MESSAGE_TYPE GetNextView() const;
 
         void ShowChatLog();
         void HideChatLog();
@@ -259,7 +275,16 @@ namespace mu::ui::window
 
     protected:
         type_vector_msgs* GetMsgs(MESSAGE_TYPE MsgType);
-        void ProcessAddText(const type_string& strID, const type_string& strText, MESSAGE_TYPE MsgType, MESSAGE_TYPE ErrMsgType);
+        void AddTextToViews(const type_string& strID, const type_string& strText, MESSAGE_TYPE MsgType,
+                            MESSAGE_TYPE ErrMsgType, bool bExternal);
+        void ProcessAddText(const type_string& strID, const type_string& strText, MESSAGE_TYPE MsgType,
+                            MESSAGE_TYPE ErrMsgType, bool bExternal);
+        void AppendMessage(type_vector_msgs* pvecMsgs, const type_string& strID, const type_string& strText,
+                           MESSAGE_TYPE MsgType, bool bExternal);
+        // The view a message is copied to besides its own and "all": the
+        // error's origin, or the Discord view. Null for none.
+        type_vector_msgs* GetSecondaryMsgs(MESSAGE_TYPE MsgType, MESSAGE_TYPE ErrMsgType, bool bExternal);
+        bool IsInCurrentView(MESSAGE_TYPE MsgType, bool bExternal) const;
 
         void SeparateText(IN const type_string& strID, IN const type_string& strText, MESSAGE_TYPE MsgType,
                           OUT type_string& strText1, OUT type_string& strText2);
diff --git a/tests/ui/CMakeLists.txt b/tests/ui/CMakeLists.txt
index eaa25adc70..213ab6bc50 100644
--- a/tests/ui/CMakeLists.txt
+++ b/tests/ui/CMakeLists.txt
@@ -77,6 +77,16 @@ mu_add_test(
     LINK_LIBS MuClient
 )
 
+# The chat log pulls in client globals defined in Winmain.cpp, so it is linked
+# here (same as test_audio_playback).
+mu_add_test(
+    NAME external_chat_tests
+    SOURCES
+        test_external_chat.cpp
+        ${CMAKE_SOURCE_DIR}/src/source/App/Platform/Windows/Winmain.cpp
+    LINK_LIBS MuClient
+)
+
 mu_add_test(
     NAME help_pages_tests
     SOURCES test_help_pages.cpp
diff --git a/tests/ui/test_external_chat.cpp b/tests/ui/test_external_chat.cpp
new file mode 100644
index 0000000000..1013690fc7
--- /dev/null
+++ b/tests/ui/test_external_chat.cpp
@@ -0,0 +1,106 @@
+// doctest unit tests for chat messages written outside the game (Discord,
+// #700): how their sender is shown, which chat they belong to, and the chat
+// log's Discord view.
+//
+// Run: ctest --test-dir <build directory> --build-config Release -R "External chat"
+
+#include "App/stdafx.h"
+#include "doctest.h"
+
+#include "UI/Chat/ExternalChat.h"
+#include "UI/HUD/ChatLogWindow.h"
+
+#include <string>
+
+using namespace UI::Chat::External;
+using mu::ui::window::CChatLogWindow;
+
+namespace
+{
+// Short enough that the chat log keeps it on one line without measuring it.
+constexpr const wchar_t* ShortText = L"hi guild";
+} // namespace
+
+TEST_CASE("External chat marks the sender with where they wrote [ui][chat]")
+{
+    CHECK(SenderLabel(Source::Discord, L"Sven") == L"[Discord] Sven");
+}
+
+TEST_CASE("External chat keeps a Discord name longer than a character's, up to its limit [ui][chat]")
+{
+    const std::wstring longName(MaxDisplayNameLength + 8, L'n');
+    CHECK(SenderLabel(Source::Discord, longName) == L"[Discord] " + longName.substr(0, MaxDisplayNameLength));
+}
+
+TEST_CASE("External chat recognises senders bridged from Discord by their prefix [ui][chat]")
+{
+    CHECK(IsBridgedSender(L"@Hero"));
+    CHECK_FALSE(IsBridgedSender(L"Hero"));
+    CHECK_FALSE(IsBridgedSender(L"@"));
+    CHECK_FALSE(IsBridgedSender(L""));
+}
+
+TEST_CASE("External chat takes the colours of its scope [ui][chat]")
+{
+    CHECK(ScopeMessageType(Scope::Guild) == mu::ui::window::TYPE_GUILD_MESSAGE);
+    CHECK(ScopeMessageType(Scope::Alliance) == mu::ui::window::TYPE_UNION_MESSAGE);
+    CHECK(ScopeMessageType(Scope::World) == mu::ui::window::TYPE_CHAT_MESSAGE);
+}
+
+TEST_CASE("External chat cuts the text to an in-game chat message [ui][chat]")
+{
+    const std::wstring longText(500, L'x');
+    CHECK(ShownText(longText).size() < longText.size());
+    CHECK(ShownText(ShortText) == ShortText);
+}
+
+TEST_CASE("External chat is listed in its scope, among all messages and in the Discord view [ui][chat]")
+{
+    CChatLogWindow chatLog;
+    chatLog.AddExternalText(SenderLabel(Source::Discord, L"Sven"), ShortText, mu::ui::window::TYPE_GUILD_MESSAGE);
+
+    CHECK(chatLog.GetNumberOfLines(mu::ui::window::TYPE_GUILD_MESSAGE) == 1);
+    CHECK(chatLog.GetNumberOfLines(mu::ui::window::TYPE_ALL_MESSAGE) == 1);
+    CHECK(chatLog.GetNumberOfLines(mu::ui::window::TYPE_DISCORD_MESSAGE) == 1);
+}
+
+TEST_CASE("In-game chat stays out of the Discord view [ui][chat]")
+{
+    CChatLogWindow chatLog;
+    chatLog.AddText(L"Player", ShortText, mu::ui::window::TYPE_GUILD_MESSAGE);
+
+    CHECK(chatLog.GetNumberOfLines(mu::ui::window::TYPE_GUILD_MESSAGE) == 1);
+    CHECK(chatLog.GetNumberOfLines(mu::ui::window::TYPE_DISCORD_MESSAGE) == 0);
+}
+
+TEST_CASE("F2 toggles all messages and whispers while nothing came from Discord [ui][chat]")
+{
+    CChatLogWindow chatLog;
+    CHECK(chatLog.GetNextView() == mu::ui::window::TYPE_WHISPER_MESSAGE);
+
+    chatLog.ChangeMessage(mu::ui::window::TYPE_WHISPER_MESSAGE);
+    CHECK(chatLog.GetNextView() == mu::ui::window::TYPE_ALL_MESSAGE);
+}
+
+TEST_CASE("F2 also offers the Discord view once something came from Discord [ui][chat]")
+{
+    CChatLogWindow chatLog;
+    chatLog.AddExternalText(SenderLabel(Source::Discord, L"Sven"), ShortText, mu::ui::window::TYPE_CHAT_MESSAGE);
+
+    chatLog.ChangeMessage(mu::ui::window::TYPE_WHISPER_MESSAGE);
+    CHECK(chatLog.GetNextView() == mu::ui::window::TYPE_DISCORD_MESSAGE);
+
+    chatLog.ChangeMessage(mu::ui::window::TYPE_DISCORD_MESSAGE);
+    CHECK(chatLog.GetNextView() == mu::ui::window::TYPE_ALL_MESSAGE);
+}
+
+TEST_CASE("An error is still listed among the messages that caused it [ui][chat]")
+{
+    CChatLogWindow chatLog;
+    chatLog.AddText(L"", L"not online", mu::ui::window::TYPE_ERROR_MESSAGE, mu::ui::window::TYPE_WHISPER_MESSAGE);
+
+    CHECK(chatLog.GetNumberOfLines(mu::ui::window::TYPE_ERROR_MESSAGE) == 1);
+    CHECK(chatLog.GetNumberOfLines(mu::ui::window::TYPE_WHISPER_MESSAGE) == 1);
+    CHECK(chatLog.GetNumberOfLines(mu::ui::window::TYPE_ALL_MESSAGE) == 1);
+    CHECK(chatLog.GetNumberOfLines(mu::ui::window::TYPE_DISCORD_MESSAGE) == 0);
+}