John V came to the throne at age eight. His reign began with an immediate civil war between his designated regent, his father's friend John VI Kantakouzenos, and a self-proclaimed council of regency composed of his mother Anna, the patriarch John XIV Kalekas, and the "megas doux" Alexios Apokaukos. During this civil war in 1343 Anna pawned the Byzantine crown jewels for 30,000 Venetian ducats. From 1346 to 1349, the Black Death devastated Constantinople.