After suppressing Cüneyt Bey's revolt, Mehmet 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, Mehmet gained contingents of troops from western Anatolia. Upon reaching the straits, Mehmet's army was given passage by ships loaned from Manuel II Palaiologos, who also supplied Mehmet with some troops.