William II probably joined his uncle, Ranulf I de Soules, at the Scottish court as a young man.
In 1174, believing Henry II to be distracted by the fighting in France, William the Lion attempted to regain Northumberland for Scotland.
[10][12][13] The barony, which was granted as a hereditary right (in feu and heritage), awarded the privileges associated with that rank, including the right to hold a judicial court and to retain the fines imposed (sake and soke), the right to exact tolls and to hold a market (toll and team), and the right to hang thieves caught red-handed (infangthief).
The charter remains preserved in their family papers,[12] while the artificial mound (motte) on which William II de Haya built his wooden tower in the twelfth century still existed at Erroll in 1967.
Sometime before 1187, William II de Haya granted the lands of Ederpolls to Coupar Angus Abbey for the benefit of the souls of King Malcolm; his uncle Ranulf de Soulis, and others, which grant was confirmed by King William, ostensibly between 1187 and 1195, although these dates are thought by Barrow to be too late.
[21] William II was still alive in 1201, as proved by a charter in the Benholm Charter-chest of that date, but apparently died soon afterwards.
The above biography of William II de Haya appears to be correct and is based on The Scots Peerage.