John VII - Basileus of Basileía Rhōmaíōn from 1390 to 1390
John VII was Byzantine Emperor for five months in 1390. While he was Emperor, there is evidence showing he used the name Andronikos, after his father, although when he was regent during his brother's absence in the West, he governed in his birth name.

When his father Andronikos IV usurped the throne from his father John V in 1376, John VII was associated as co-emperor the following year. Both father and son were overthrown and partly blinded in 1379, but Andronikos IV kept his imperial status and was granted Selymbria (Silivri) as his domain by John V. In 1390 John VII ousted his grandfather John V and maintained himself on the throne for five months, until John V was restored by his son Manuel with the help of the Republic of Venice.

John VII sought refuge with Bayezid I of the Ottoman Empire on 17 September 1390. He was restored as the ruler of Selymbria, only to turn on Bayezid in 1399. When Bayezid was defeated by Timur in 1402, he conquered much of western Anatolia for the Empire.

On Manuel II's return John VII dutifully returned power to him and was allowed to retire to Thessalonica.
John VII
Emperor John VII of the Byzantine Empire