Alastair Ruadh MacDonnell
Alastair (i.e. Alexander) Ruadh MacDonnell (in the Gaelic "Alasdair Ruadh Mac Dhomhnuil", i.e. "Red Alexander") lived (c. 1725 – 23 December 1761), and was a chief of Clan MacDonell of Glengarry, a Scottish Jacobite who was 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 Clan Donald, but spelt their name Macdonnell or Macdonell (reflecting the Gaelic pronunciation of the name). His father was John, twelfth chief of Glengarry, a violent and brutal man who is said to have starved his first wife, Alastair's mother, to death on an island in the Hebrides. Alastair 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 of London 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. Alastair, 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 one Cameron woman, whose husband he betrayed to death in 1752, he never lost the confidence of the Jacobite leaders and was probably responsible for the betrayal and execution of Dr. Archibald Cameron of Locheil in 1753. On the death of his father, in 1754, he succeeded to the estates, and proved himself a greedy landlord.
See Andrew Lang, Pickle the Spy (1897) and The Companions of Pickle (1898).