Saruhan Bey seized Manisa from the Byzantinians in 1313 on the holy night of Regaip and put an end to the sovereignty of Byzantium. The name of the city which becomes the center of the principality was then changed into Manisa. Since then, the people of the city celebrates that day on the Holy day of Regaip. The tomb of Saruhan Bey who died in 1348 was built by his grandson İshak Çelebi in the west of Muradiye Mosque.