Accused with his brother, William Douglas of Whittingehame, of involvement in the conspiracy to murder David Riccio, he was obliged to retire to France for some time.
But the husband of Mary, Queen of Scots, Henry Stuart, Lord Darnley, secured his return to Scotland, where Douglas then successfully negotiated the pardons of the other conspirators, gazetted on 25 December 1566.
In April 1572 he was arrested following the discovery that he was assisting the party of Mary, Queen of Scots and Sir William Kirkcaldy of Grange who held Edinburgh Castle, by bringing money sent from the Duke of Alba from the Spanish Netherlands.
[5] Ten years after these events, the English diplomat Thomas Randolph wrote to Francis Walsingham to certify that Drury had found Mr Archibald a "fit instrument" to secretly negotiate with Grange, William Maitland of Lethington, Melville, and others, especially to persuade them to surrender the castle.
On 28 November 1581, he was forfeited by Act of Parliament for the murder of Lord Darnley, which, they argued, was proved by his flight to England, and the evidence of his servant Thomas Binning, who had, in June 1581, already been executed for the same crime.
William Fowler wrote to Walsingham that although Douglas had denied that knew how to write letters in cipher code, he was "well practised in the that art".
[11] As the Babington Plot concerning Mary, Queen of Scots, was revealed, James VI sent Douglas to Elizabeth as a confidential messenger in July 1586.
Douglas was to discuss the question of James's claim to the English throne with the Earl of Leicester, and ask for advice about his marriage plans.
John Mowbray, Laird of Barnbougle, wrote to Douglas encouraging him, saying that otherwise James would revenge his mother's death by waging war.
A Mr. Archibald Douglas, Archdeacon of Glasgow (in that post prior to November 1596), is mentioned in the Privy Council Registers on 28 October 1598, and again on 4 December 1599, but it is not known if this is the same person.
In January 1601 his sister, Jean Douglas, Lady Saltcoats, wrote to him for fine London cloth for gowns for her daughters, who were of age to married.
Bacon later tried to pawn the ring with the same London goldsmith, who said it was worth only half the amount that Foulis had allowed for in the royal accounts.
[20] Archibald Douglas married, about 1578, (as her third husband) Jane (d. before August 1599), daughter of Patrick Hepburn, 3rd Earl of Bothwell.