Editing Ottoman Interregnum (section)

==Civil war==
===İsa and Mehmed===
Civil war broke out among the sons of Sultan [[Bayezid I]] upon his death in 1403. His oldest son, [[Süleyman Çelebi|Süleyman]], with his capital at [[Edirne]], ruled the recently-conquered [[Second Bulgarian Empire]], all of [[Thrace]], [[Macedonia (region)|Macedonia]], and northern [[Greece]]. The second son, [[İsa Çelebi]], established himself as an independent ruler at [[Bursa, Turkey|Bursa]],{{sfn|Kastritsis|2007|p=79}} and Mehmed formed a kingdom at [[Amasya]].{{sfn|Kastritsis|2007|p=73}} War broke out between Mehmed and İsa, and following the Battles of Ermeni-beli{{sfn|Pitcher|1968|p=59}} and of [[Battle of Ulubad|Ulubad]] (March–May 1403),{{sfn|Kastritsis|2007|p=79}} İsa fled to Constantinople, and Mehmed occupied Bursa.{{sfn|Kastritsis|2007|pp=90–91}} The subsequent battle at Karasi between Mehmed and İsa resulted in Mehmed's victory and Isa fleeing to [[Karaman]].{{sfn|Pitcher|1968|p=59}} İsa was later killed in a bath by agents of Mehmed.{{sfn|Kastritsis|2007|pp=109–110}}

===Süleyman enters civil war===
Meanwhile, the other surviving son of Bayezid, [[Musa Çelebi]], who was captured at the [[Battle of Ankara]], was released by [[Timur]] into the custody of Yakub of [[Germiyan]].{{sfn|Kastritsis|2007|p=85}} Musa was freed after Mehmed made a request for his brother's release. Following İsa's death, Süleyman crossed the straits with a large army.{{sfn|Kastritsis|2007|p=110}} Initially, Süleyman was successful. He invaded Anatolia, capturing Bursa (March&nbsp;1404){{sfn|Kastritsis|2007|p=112}} and Ankara later that year.

During the stalemate in Anatolia, which lasted from 1405 to 1410, Mehmed sent Musa across the [[Black Sea]] to [[Thrace]] with a small force to attack Süleyman's territories in south-eastern Europe. The maneuver soon recalled Süleyman to Thrace, where a short but sanguinary contest between him and Musa ensued. At first, Süleyman had the advantage and won the [[Battle of Kosmidion]] in 1410, but in 1411 his army defected to Musa at Edirne. Süleyman was captured, given to Musa's bodyguard, Koyun Musasi, and strangled to death on 17 February 1411.{{sfn|Finkel|2006|p=32}}{{sfn|Kastritsis|2007|pp=155–156}} Musa was now the ruler of the Ottoman dominions in Thrace.

===Mehmed and Musa===
[[Manuel II Palaiologos]], the Byzantine emperor, had allied with Süleyman. Mûsa, therefore, [[Siege of Constantinople (1411)|besieged Constantinople]].{{sfn|Ostrogorsky|1969|p=557}} Manuel called on Mehmed to protect him, and Mehmed's Ottomans now garrisoned Constantinople against Musa's Ottomans of Thrace. Mehmed made several unsuccessful sallies against his brother's troops and was obliged to recross the [[Bosporus]] to quell a revolt that had broken out in his own territories. Musa now pressed the siege of Constantinople. Mehmed returned to Thrace, and obtained the assistance of [[Stefan Lazarevic]], the [[Despotate of Serbia|Serbian Despot]].

The armies of the rival Ottoman brothers met on the [[Battle of Camurlu|Plain of Chamurli]] (now [[Samokov]], [[Bulgaria]]). Hassan, the [[Agha (Ottoman Empire)|Agha]] of the [[Janissaries]] of Mehmed, stepped out before the ranks and tried to get the troops to change sides. Musa rushed towards Hassan and killed him, but was himself wounded by an officer who had accompanied Hassan. Musa's Ottomans fought well, but the battle was won by Mehmed and his allies.{{sfn|Spuler|Bagley|Kissling|1996|p=14}} Musa fled but was later captured and strangled.{{sfn|Nicol|1972|p=327}} With Musa dead, Mehmed was the sole surviving son of the late Sultan Bayezid I and became Sultan Mehmed I.

The Interregnum was a striking example of the [[fratricide]] that would become common in Ottoman successions.