Mustafa II
Osman III was born on January 2, 1699 in the Edirne Palace. His father was Mustafa II and his mother was Şehsuvar Sultan. He was the younger half-brother of Mahmud I. When his father was deposed from the throne in 1703, he was taken back to Istanbul and imprisoned in the Kafes. Osman III lived in the Kafes for 51 years.