The Kingdom of Brittany was a short-lived vassal-state of the Frankish Empire that emerged during the Norman invasions. Its history begins in 851 with Erispoe's claim to kingship. In 856, Erispoe was murdered and succeeded by his cousin Salomon. The kingdom fell into a period of turmoil caused by Norman invasions and a succession dispute between Solomon's murderers: Gurvand and Pascweten. Pascweten's brother, Alan, called the Great, was the third and last to be recognized as king of Brittany. After his death, Brittany fell under Norman occupation. When Alan Twistedbeard, Alan the Great's grandson, reconquered Brittany in 939, Brittany became a duchy until its union with France in 1532.