When Ivan Asen III became emperor at Tărnovo in 1279 during the Uprising of Ivaylo, he sought to strengthen his position by allying himself with George Terter. The latter divorced his first wife Maria, who was sent together with their son Theodore Svetoslav as a hostage to the Byzantine Empire, to marry Maria (Kira Maria), the sister of Ivan Asen III. George Terter was accordingly made a despot, the highest rank in the Byzantino-Bulgarian court hierarchy.