Sersem Ali Baba was an Ottoman Bektashi dervish who arrived in Kalkandelen (Tetovo) around 1551 and is regarded as the founder of the Harabati Baba Bektashi tekke. Sources record his death around 1569, though some traditions hold that he died in Najaf, which would make the twelve-sided structure at Tetovo a commemorative shrine rather than an actual grave. The tekke that grew around his türbe is among the best-preserved Bektashi complexes in the Balkans. (Sources: TDV İslâm Ansiklopedisi 'Harâbâtî Baba Tekkesi'; Wikipedia 'Arabati Baba Teḱe')