It began in 1402, when chaos reigned in the Ottoman Empire following the defeat of Sultan Bayezid I by the Turco-Mongol warlord Timur (Tamerlane). Although Mehmed Çelebi was confirmed as sultan by Tamerlane, his brothers refused to recognise his authority. Civil war was the result. The Interregnum lasted until 1413, when Mehmed Çelebi emerged as victor in the strife, crowned himself sultan as Mehmed I, and restored the empire.