Given the following passage  "With the extension of Turkish dominion into the Balkans, the strategic conquest of Constantinople became a crucial objective. The empire had managed to control nearly all former Byzantine lands surrounding the city, but in 1402 the Byzantines were temporarily relieved when the Turco-Mongol leader Timur, founder of the Timurid Empire, invaded Anatolia from the east. In the Battle of Ankara in 1402, Timur defeated the Ottoman forces and took Sultan Bayezid I as a prisoner, throwing the empire into disorder. The ensuing civil war lasted from 1402 to 1413 as Bayezid's sons fought over succession. It ended when Mehmed I emerged as the sultan and restored Ottoman power, bringing an end to the Interregnum, also known as the Fetret Devri.",  answer the following question. Note that the answer is present within the text.  Question: What happened before the civil war, the Battle of Ankara or Mehmed I emerging as the sultan?
The answer to this question is:
the Battle of Ankara