Conversation so far:
When was Fethullah Gulen's split with President erdogan?
Analysts believed that a number of arrests made against allies of Recep Tayyip Erdoğan reflect a power struggle between him and Fethullah Gülen. These arrests led to a corruption scandal.

Question: Who was Erdogan?
Self-contained rewrite: Who was Recep Tayyip Erdogan?