Conversation so far:
What were the earliest sources on the Battle of Kosovo with Miloš Obilić?
The earliest sources on the Battle of Kosovo with Miloš Obilić, which generally favour the cult of Prince Lazar, do not mention Miloš or his assassination of the sultan.

Question: What was the assassination of the sultan?
Self-contained rewrite: What was the assassination of the sultan that the earliest sources on the Battle of Kosovo, which generally favour the cult of Prince Lazar did not mention?