The Columbia Encyclopedia, Sixth Edition. 2001-07.
John VII, Byzantine emperor
(John Palaeologus) (p´´ll´gs) (KEY) , c.13701408, Byzantine emperor, grandson of John V. Backed by the sultan Beyazid I, he usurped (1390) the throne from John V but was dethroned by his uncle, Manuel II, six months later. He again ruled (13991402) as coemperor when Manuel II went to the West to seek aid against the Turks.