1911 Encyclopædia Britannica/Macdonnell, Alestair Ruadh
MACDONNELL (or Macdonell), ALESTAIR (i.e. Alexander) RUADH (c. 1725–1761), chief of Glengarry, a Scottish Jacobite who has been identified by Andrew Lang as the secret agent “Pickle,” who acted as a spy on Prince Charles Edward after 1750. The family were a branch of the clan Macdonald, but spelt their name Macdonnell or Macdonell. His father was John, 12th chief of Glengarry, a violent and brutal man, who is said to have starved his first wife, Alestair’s mother, to death on an island in the Hebrides. Alestair ran away to France while a mere boy in 1738, and there entered the Royal Scots, a regiment in the French service. In 1743 he commanded a company in it, and in 1744 was sent to Scotland as a Jacobite agent. In January 1745 he was sent back with messages, and was in France when Prince Charles Edward landed in Scotland. Late in 1745 he was captured at sea while bringing a picquet of the Royal Scots to help the prince. He remained a prisoner in the Tower for twenty-two months, and when released went abroad. In 1744 his father had made a transfer to him of the family estates, which were ruined. Alestair, who still affected to be a Jacobite, lived for a time in great poverty. In 1749 he was in London, and there is good reason to believe that he then offered his services as a spy to the British government, with which he communicated under the name of Pickle. His information enabled British ministers to keep a close watch on the prince and on the Jacobite conspiracies. Though he was denounced by a Mrs Cameron, whose husband he betrayed to death in 1752, he never lost the confidence of the Jacobite leaders. On the death of his father, in 1754, he succeeded to the estates, and proved himself a greedy landlord. He died on the 23rd of December 1761.
See Andrew Lang, Pickle the Spy (1897) and The Companions of Pickle (1898).