The Ottoman Interregnum (Turkish: Fetret Devri) was a period at the beginning of the fifteenth century, in which chaos prevailed in the Ottoman empire after the captivation of Bayezid I by Timoer Lenk in 1402 and his death in 1403. The period lasted until 1413 when Mehmet I Çelebi came out as a victor, erupted himself to sultan and restored the Empire.
Süleyman Çelebi ruled over northern Greece, Bulgaria and Thrace and his brother İsa Çelebi across Greece and West Anatolia. However, İsa Çelebi was shot by his younger half-brother Mehmet Çelebi from the throne when Mehmet conquered Bursa's capital in 1404. Süleyman knew when to take over southern Greece while Mehmet ruled over Anatolia. Mehmet eventually sent his younger brother Musa with an army over the Bosphorus to defeat Süleyman. Musa managed to win in Bulgaria in 1410, after which Süleyman returned to Greece.
Musa then called himself to the Ottoman Empire sultan to which Mehmet reacted wildly and sent a small army to Gallipoli but he was defeated. Mehmet decided to close an alliance with the Byzantine Empire and three years later he sent a new army that beat Musa at Kamerlu, Serbia. It was then easy to punch his last brother from the throne after which he became Ottoman sultan.
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