The two brought their sister Rita of Armenia to Constantinople to marry the Byzantine emperor Michael IX Palaiologos in 1296,[1] but were imprisoned upon their return in Bardzrberd by their brother Sempad, who had usurped the throne in their absence.
Thoros was murdered, strangled to death on 23 July 1298, in Bardzrberd by Oshin, Marshal of Armenia, on Sempad's orders.
Thoros was married twice; his first marriage, to Margaret of Lusignan (ca 1276–1296, Armenia) (the daughter of King Hugh III of Cyprus), took place on 9 January 1288.
[2] His only son, by his first marriage, was Leo III of Armenia, who became heir to his uncle Hethum II.
Leo ruled from 1303 to 1307, but was murdered along with his uncle by the Mongol general Bilarghu at a feast.