In 877 fighting the Vikings in Fife, Constantine was killed. The throne passed to his brother Aed, as his son was considered too young to be king as he was only around 10 at the time. When Aed died in 878 the throne passed to Donald I, his uncle's son, Constantine's cousin Giric who ruled from 878-889, then finally followed by Constantine's son, Donald II, the last Pictish king who ruled from 889-900, all monarchs after him were styled "King of Alba" or Rex Alban