The wadset (a loan masked as a sale of land under right of reversion) of the Lordship had been set aside, and annexed to the Commonwealth in 1657.
However, this too was pronounced null and void, and the islands were vested in the Crown by the Orkney and Shetland Act 1669 on 17 December 1669.
On 9 September 1672 he resigned the Barony of Dalkeith in favour of James Scott, 1st Duke of Monmouth.
The estate of Dalkeith and other lands, to the total value of £100,000 Scots yearly rental,[3] had been sold circa 1643 to Buccleuch to enable the 7th Earl meet his expenses supporting the King.
[3] William died in 1681 leaving no heir, passing the Earldom to his uncle, James Douglas, 10th Earl of Morton, who was the son of William Douglas, 7th Earl of Morton and Lady Anne Keith.