diff --git a/locale/de/LC_MESSAGES/django.po b/locale/de/LC_MESSAGES/django.po
index 0b0fc7f..89847e7 100644
--- a/locale/de/LC_MESSAGES/django.po
+++ b/locale/de/LC_MESSAGES/django.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2021-03-20 19:33+0100\n"
+"POT-Creation-Date: 2021-04-21 14:09+0200\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -1522,7 +1522,7 @@ msgid "Wagtail search tests"
 msgstr ""
 
 #: bla/lib/python3.7/site-packages/wagtail/tests/settings.py:239
-#: config/settings/base.py:219
+#: config/settings/base.py:220
 msgid "English"
 msgstr "Englisch"
 
@@ -2000,7 +2000,7 @@ msgstr ""
 msgid "Edit this video"
 msgstr ""
 
-#: config/settings/base.py:220
+#: config/settings/base.py:221
 msgid "German"
 msgstr "Deutsch"
 
@@ -2150,23 +2150,23 @@ msgstr "Endzeit"
 msgid "Room"
 msgstr "Raum"
 
-#: mpicms/events/models.py:44
+#: mpicms/events/models.py:46
 msgid "event dates"
 msgstr "Veranstaltungsdaten"
 
-#: mpicms/events/models.py:106
+#: mpicms/events/models.py:96
 msgid "event"
 msgstr "Veranstaltung"
 
-#: mpicms/events/models.py:107
+#: mpicms/events/models.py:97
 msgid "events"
 msgstr "Veranstaltungen"
 
-#: mpicms/events/models.py:148
+#: mpicms/events/models.py:138
 msgid "event index"
 msgstr "Veranstaltungs-Index"
 
-#: mpicms/events/models.py:149
+#: mpicms/events/models.py:139
 msgid "event indexes"
 msgstr "Veranstaltungs-Indexes"
 
@@ -2303,7 +2303,15 @@ msgstr "Veranstaltungen der Woche"
 msgid "All events"
 msgstr "Alle Veranstaltungen"
 
-#: mpicms/templates/events/event_index.html:11
+#: mpicms/templates/events/event_index.html:5
+msgid "hide external events"
+msgstr "Externe Events verbergen"
+
+#: mpicms/templates/events/event_index.html:6
+msgid "show external events"
+msgstr "Externe Events zeigen"
+
+#: mpicms/templates/events/event_index.html:15
 msgid "Subscribe"
 msgstr "Abonnieren"
 
diff --git a/mpicms/events/migrations/0015_event_external.py b/mpicms/events/migrations/0015_event_external.py
new file mode 100644
index 0000000..c1bbe40
--- /dev/null
+++ b/mpicms/events/migrations/0015_event_external.py
@@ -0,0 +1,18 @@
+# Generated by Django 3.1.7 on 2021-03-21 11:49
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('events', '0014_auto_20210114_1926'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='event',
+            name='external',
+            field=models.BooleanField(default=False),
+        ),
+    ]
diff --git a/mpicms/events/models.py b/mpicms/events/models.py
index 2b3d55a..b0920c6 100644
--- a/mpicms/events/models.py
+++ b/mpicms/events/models.py
@@ -20,6 +20,7 @@ class Event(BodyMixin, BasePage):
     start_time = models.TimeField(_('start time'), blank=True, null=True)
     end_time = models.TimeField(_('end time'), blank=True, null=True)
     room = models.CharField(_('Room'), max_length=10, blank=True)
+    external = models.BooleanField(default=False)
 
     header_image = models.ForeignKey(
         'wagtailimages.Image',
@@ -36,6 +37,7 @@ class Event(BodyMixin, BasePage):
         ImageChooserPanel('header_image'),
         MultiFieldPanel(
             [
+                FieldPanel('external'),
                 FieldPanel('start_date'),
                 FieldPanel('start_time'),
                 FieldPanel('end_date'),
@@ -74,7 +76,6 @@ def get_dict(self, request=None):
             'start': self.start.isoformat(),
             'end': self.end.isoformat() if self.end else None,
             'url': self.get_url(request=request),
-            'color': '#006c66'
         }
 
     def clean(self):
@@ -90,17 +91,6 @@ def clean(self):
         if self.end and self.end < self.start:
             raise ValidationError({'end_time': 'The end time cannot be before the start time.'})
 
-    def get_context(self, request, *args, **kwargs):
-        context = super().get_context(request, *args, **kwargs)
-
-        events = []
-        for child in self.get_parent().get_children().type(Event).live().specific():
-            events.append(child.get_dict(request))
-
-        context["events"] = json.dumps(events)
-
-        return context
-
     class Meta(object):  # noqa
         ordering = ['start_date']
         verbose_name = _('event')
@@ -117,8 +107,8 @@ def events(self):
             return Event.objects.live().specific()
         return self.get_children().type(Event).live().specific()
 
-    def get_json_events(self, request=None):
-        event_dicts = [event.get_dict(request) for event in self.events]
+    def get_json_events(self, request=None, external=False):
+        event_dicts = [ event.get_dict(request) for event in self.events.filter(external=external) ]
         return json.dumps(event_dicts)
 
     def clean(self):  # Prevent more than one event index
diff --git a/mpicms/events/templatetags/event_tags.py b/mpicms/events/templatetags/event_tags.py
index d7d0aac..615c62d 100644
--- a/mpicms/events/templatetags/event_tags.py
+++ b/mpicms/events/templatetags/event_tags.py
@@ -5,5 +5,5 @@
 
 
 @register.simple_tag(takes_context=True)
-def get_json_events(context, event_index):
-    return event_index.get_json_events(request=context['request'])
+def get_json_events(context, event_index, external=False):
+    return event_index.get_json_events(request=context['request'], external=external)
diff --git a/mpicms/static/css/custom.css b/mpicms/static/css/custom.css
index 3dadad0..20424a7 100644
--- a/mpicms/static/css/custom.css
+++ b/mpicms/static/css/custom.css
@@ -761,3 +761,12 @@ div.codehilite:not(:last-child) {
     width: 100%;
     height: 100%;
 }
+
+#switch_external {
+    color: black;
+    background-color: silver;
+}
+
+#switch_external:hover {
+    background-color: lightgray;
+}
diff --git a/mpicms/templates/events/event.html b/mpicms/templates/events/event.html
index 73b4f33..11d569d 100644
--- a/mpicms/templates/events/event.html
+++ b/mpicms/templates/events/event.html
@@ -36,6 +36,11 @@ <h2 class="title is-2">{{ page.title }}</h2>
             </div>
         {% endif %}
 
+        {% if page.external %}
+            <div class="tag is-medium">
+                external
+            </div>
+        {% endif %}
 
         {% if page.room %}
             <div class="tag is-medium">
diff --git a/mpicms/templates/events/event_index.html b/mpicms/templates/events/event_index.html
index e10110e..bc82363 100644
--- a/mpicms/templates/events/event_index.html
+++ b/mpicms/templates/events/event_index.html
@@ -2,25 +2,38 @@
 {% load event_tags i18n %}
 
 {% block content %}
+    {% translate "hide external events" as txt_hide_external_events %}
+    {% translate "show external events" as txt_show_external_events %}
     <div class="section">
 
         <h2 class="title is-2">{{ page.title }}</h2>
 
         <div id="calendar"></div>
         <br>
-        <a href="https://it.molgen.mpg.de/cgi-bin/ics/subscription?cal=molgen&subscribe=1" class="button cal-button">{% trans 'Subscribe' %}</a>
-
+        <div class="fc-toolbar">
+            <div class="fc-left">
+                <a href="https://it.molgen.mpg.de/cgi-bin/ics/subscription?cal=molgen&subscribe=1" class="button cal-button">{% trans 'Subscribe' %}</a>
+            </div>
+            <div class="fc-center">
+            </div>
+            <div class="fc-right">
+                <a id="switch_external" class="button">{{ txt_hide_external_events }}</a>
+            </div>
+        </div>
     </div>
 
-    {% get_json_events page as events %}
+{% autoescape off %}
     <script>
 
+        var event_source_internal = { events: {% get_json_events page %}, color: '#006c66' };
+        var event_source_external = { events: {% get_json_events page True %}, color: 'silver', textColor: 'black' };
+
         document.addEventListener('DOMContentLoaded', function() {
             var calendarEl = document.getElementById('calendar');
 
             var calendar = new FullCalendar.Calendar(calendarEl, {
                 plugins: [ 'dayGrid', 'timeGrid' ],
-                events: {{ events|safe }},
+                eventSources: [ event_source_internal , event_source_external ],
                 locale: '{{ LANGUAGE_CODE }}',
                 header: {
                     left:   'dayGridMonth,timeGridWeek,timeGridDay',
@@ -29,9 +42,24 @@ <h2 class="title is-2">{{ page.title }}</h2>
                 }
             });
 
+            var externalEventsShown = 1
+
+            document.getElementById('switch_external').addEventListener("click", function() {
+                if (externalEventsShown) {
+                    calendar.getEventSources()[1].remove()
+                    externalEventsShown = 0
+                    this.innerHTML="{{ txt_show_external_events }}"
+                } else {
+                    calendar.addEventSource(event_source_external)
+                    externalEventsShown = 1
+                    this.innerHTML="{{ txt_hide_external_events }}"
+                }
+            });
+
             calendar.render();
         });
 
     </script>
+{% endautoescape %}
 
 {% endblock %}