Battle of Çamurlu

Mehmed's invasion and final battle

After suppressing Cüneyt Bey's revolt, Mehmed Çelebi gathered his troops at Ankara. With his Dulkadirid father-in-law, he began planning an invasion of Rumelia (the European part of the empire and Musa's stronghold) to defeat his brother, Musa. On his march to Bursa, Mehmed gained contingents of troops from western Anatolia. Upon reaching the straits, Mehmed's army was given passage by ships loaned from Manuel II Palaiologos, who supplied Mehmed with some troops.

Mehmed marched his army from Constantinople to Edirne. He then marched onto Kosovo to join forces with his ally (and also half-uncle) Serbian ruler Stefan Lazarević, along with receiving information from Ewrenos concerning possible defections during the battle.

Both armies met at Çamurlu, near modern-day Samokov, south east of Sofia, Bulgaria. Initially, Musa appeared to be winning the battle despite the defection of Pasha Yigit and Sinan Bey of Trikkala. However, the tide of the battle turned in favor of Mehmed, with the help of Serb and Byzantine troops, and Musa Çelebi fled.