At the age of 16, Azariah inherited from his father Amaziah. As was told in II Kings 15: Game of thrones, the Divided Kingdom, although his reign was long, much of it he spent in confinement, stricken with leprosy.
It turns out that Uzziah, as he was also called, had several successful wars, with the Philistines, the Ammonites and others, and that other peoples paid him off to keep him from attacking him. All of this treasure enabled the king to go on a building and restoration spree, which generally improved the economy as well as his own popularity. All of this went to his head, and he tried to worship God without going through the proper Levite channels. Unfortunately, this pissed God off and that’s why he was became a leper.