Alexander (Bulgarian: Александър), subsequently Iskender (Ottoman Turkish: اسكندر) (died 1418), was the eldest son of Bulgarian tsar Ivan Shishman (r. 1371–1395). Alexander was possibly made co-emperor by his father before the Ottoman conquest of the Tarnovo Tsardom in 1395. After the subjugation of Ivan Shishman's realm and his execution, Alexander converted to Islam to avoid his father's fate. He was made governor of Samsun, where he remained until 1402. From 1413 to 1418, when he was killed in a battle against a local rebel, Alexander was in charge of Smyrna (İzmir).