Suleiman Çelebi

Type Figure Region Rumelia Time c. 1377–1411 Also known as Süleyman Çelebi、Suleiman Celebi

Eldest son of Bayezid I, he established himself in Rumelia after the Battle of Ankara in 1402, based at Edirne, allying with Byzantine Manuel II and …

Timeline

1402–1410Edirne · RumeliaWith Timur's support he controlled the Balkan side, concluding peace with Byzantium in 1403 and receiving part of Thrace. From 1401–1410 he was the strongest breakaway power on the European side, maneuvering against his brothers and Byzantium.
1410–1411Çermen (Çamurlu) · BulgariaDefeated by Musa in 1410 and losing his advantage, defeated again by Mehmed at the Battle of Çermen in February 1411, his power collapsed, he was killed, and the breakaway situation in Rumelia came to an end.

Sources

Interregnum https://www.britannica.com/topic/Ottoman-Empire/The-Ottoman-Interregnum
The Ottoman Empire, 1300-1650: The Structure of Power — Colin Imber (2009)