William Douglas, 6th Earl of Morton

William Douglas's half-brother from his mother's liaison with the king was James Stewart, Earl of Moray, Regent of Scotland from 1567 until his assassination in January 1570.

His cousin was another Regent of Scotland James Douglas, 4th Earl of Morton, and was closely associated with him in his career, the two men being occasionally confused in the histories.

[5] William's wife, Lady Agnes Leslie, became the Queen's chief female companion during her ten and a half months of imprisonment, accompanying her throughout the day and often sleeping in her bedchamber.

In Edinburgh, William Douglas helped Wood check the coffers containing Agnes Keith's clothes at Holyrood Palace and her possessions at St Andrews Castle, now in his keeping.

[9] In October 1570 William Douglas was the keeper of the Earl of Northumberland at Lochleven castle and wrote to the English diplomat Thomas Randolph mentioning that Loch Leven was liable to freeze.

While Regent Morton was on trial in January 1581, William and other leading members of the family were not allowed to come to Edinburgh, and in March he was ordered to live north of Cromarty.

[11] The 17th century historian David Hume of Godscroft relates that Agnes Leslie wrote to her husband saying she would prevent their son Robert from joining him at the Lords Enterprisers attempt to take Stirling Castle in 1584, saying it was a foolish work that would ruin them.

Margaret Winstar, a Danish servant of Anne of Denmark, helped her lover, the rebel John Wemyss of Logie escape from the palace.

James VI was angry and held a council, and sent Morton and Sir Robert Melville to the queen to demand she sent Winstar back to Denmark.

[14] William Douglas wrote a short history of the Scottish reformation and reigns of Mary and James VI briefly mentioning the Siege of Leith, the Battle of Carberry Hill, the murder of David Rizzio, and the Ruthven Raid.

1606), the daughter of Margaret Crichton and George Leslie, 4th Earl of Rothes and as a direct descendant of King James II in her maternal line.