The Wiki lists the following interesting Nestorian rulers:
Denah Yaballalah, Emir of Socotra in the 867 start
Sartag Borjigin, Khagan of the Golden Horde on January 2, 1255
Kitbuqa Noyan, High Chief of Aleppo on January 1, 1260
Abaga Borjigin, Khagan of the Ilkhanate on January 1, 1279
That...