Mustapha Khaznadar was born of Greek ancestry as Georgios Kalkias Stravelakis on the island of Chios in 1817. In January 1822, rebels from the neighboring islands of Samos arrived on Chios and declared their independence from the Ottoman Empire, the Ottoman sultan soon sent an army of about 40,000 to the island of Chios, where roughly 52,000 Greek inhabitants were massacred and tens of thousands of women and children were taken into slavery. During the Chios massacre, Georgios's father, the sailor Stephanis Kalkias Stravelakis, was killed, while Georgios along with his brother Yannis were captured and sold into slavery by the Ottomans. He was then taken to Smyrna and then Constantinople, where he was sold as a slave to an envoy of the Husainid Dynasty.