[5][6] On succeeding to the Earldom of Orkney, William had barely been in possession of it for a year when he was one of five earls selected to be among twenty hostages, proposed on 31 May 1421, for the redemption of James I of Scotland.

However, due to disorder during the reign of Menzies, the government of the earldom was reinstated to the Bishop for seven years until the young Earl William could formally receive his investiture.

[1] In 1446, the Earl of Orkney laid the foundation stone of the Collegiate Church of St Matthew, commonly referred to as Rosslyn Chapel.

[7] In the same year the Earl of Orkney was called to the Norwegian Riksråd to take the oath of Christopher of Bavaria who was the successor of King Eric of Denmark, Norway and Sweden.

[8] The same year the Earl of Orkney appears obtaining the patronage of the chapel of Saint Duthac in Kirkwall.

Hamilton was taken by the royal camp and the Earl of Orkney kept him in honourable captivity in Roslin Castle for a few days until he defected from the House of Douglas.

[1] The Norse jarldom technically remained in existence, but William now only had authority over the mainland parts - Caithness and Sutherland.

In 1472, it having become clear that the dowry was unlikely to be paid, James declared the Jarldom's territory to be forfeit to the Scottish Crown, to which it was annexed by an act of the Parliament of Scotland[which?]