 On account of the Corryvreckan whirlpool to the north of Jura, the Sound was the main safe sea route between the mainland and the rest of the Hebrides; Claig Castle essentially gave Somerled control of sea traffic.Following Somerled's 1164 death, the realm was divided between Godred's heirs, and Somerled's sons, whose descendants continued to describe themselves as "King of the Sudreys" until the 13th century.Somerled's grandson, Donald received Islay, along with Claig Castle, and the adjacent part of Jura as far north as Loch Tarbert.