William Montacute, Earl of Salisbury, who took the Isle of Man from the Scots by force and whose son sold it.

He had a claim of blood as well as a sword. Aufrica, daughter of Olave II, married Sir Simon de Montacute, and from that marriage the family reckoned itself of the race of the Kings of Man. Camden's account is that what could not be obtained by right, Sir William Montacute won by his sword, mustering a band of English in haste and driving all the Scots out of the Island, and that the war left him deeply in debt. The Wiltshire antiquaries put it that the earl bravely drove the Scots out, recovered the seigniory and crown of the Island from Edward III, and by the King's approbation was called King of Man.

The Island's position stayed unsettled for two generations. It was formally included by name in the truce between France and England of 1389, which was signed both by Thomas Randolph, Earl of Moray, as its sovereign in the Scottish interest, and by Montacute as the King of Man whom England recognised. The double signature was thought to have been suggested by the contest continuing unresolved and by the danger from pirates.

The sale ended the Montacute lordship. The second Earl, son and heir of the first, is represented in Thomas Walsingham's history, and on that authority in Selden and Dugdale, as having sold the Island and the crown of it to Sir William Scrope for a great sum of money. Scrope was afterwards beheaded for high treason and the Island fell into Henry IV's hands.