Conversation so far:
Who founded the Anthroposophical Society?
Rudolf Steiner and the majority of members of the German section of the Theosophical Society broke off to form a new group, the Anthroposophical Society
Where did the Anthroposophical Society get started?
The Anthroposophical Society was founded in Cologne, Germany, with about 3000 members.

Question: When was the Society founded?
Self-contained rewrite: When was the Anthroposophical Society founded?