Indulf (a.k.a. Illdulb mac Causantín) was King of Alba from 954 to 962. The wider picture in Scotland at the time is set out in our Historical Timeline.
His reign saw the return of Viking raids. One account talks of a fleet of 50 Viking longships appearing in the Firth of Forth and being deterred from landing by a Scottish army that then tracked them around the coast of eastern Scotland. They eventualy landed near Cullen where King Indulf's army defeated them.
In 962 King Indulf, apparently on the point of abdicating to become a monk as his father had done, came up against the Vikings again, at the Battle of the Bauds near Findochty, where he defeated Danish King Eric of the Bloody Axe.
Accounts differ about Indulf's fate. Was he killed during the Battle of the Bauds? Was he killed by Vikings near Stonehnaven? Or did he survive his many battles and retire to a monastery? Whatever happened to him in or after 962, Indulf was buried in the graveyard at Saint Oran's Chapel on the Isle of Iona.