Mehmed I, also known as Celebi Mehmed, was the 5th sultan of the Ottoman dynasty. He was born in Bursa in 1389 and died in Edirne in 1421, he was buried in his mausoleum at the Green Tomb in Bursa. His father was Yildirim Bayezid and mother was Devlet Hatun.
After the defeat of sultan Yildirim Beyazit by Tamerlane in 1402, the Ottoman territories were divided among three of Bayezid's sons and thus Mehmed ruled in Amasya area. Mehmed fought with his brothers between 1402 - 1413 and after winning the battles he reunified the dismembered Ottoman territories, ruling the Empire until 1421. Therefore he's known as the "second founder" of the Ottoman Empire.
During his rule, Mehmet I faced several problems and risks such as his other brother, Mustafa, fighting against him. Then his nephew Orhan organizing a plot for overthroning Mehmet, and then rebellions against the throne. Between 1414-1420 he captured Karaman Principality and Candar Principality, captured some parts of the Balkans and fought against Venetians.