Glengarry's Regiment served throughout the 1745 Rising, initially led by Aeneas, Glengarry's second son; he was accidentally shot dead after Falkirk and replaced by his kinsman Lochgarry who commanded at the Battle of Culloden. His elder brother Alastair, later 13th Glengarry was captured by a British frigate in November 1745 when travelling from France to join the Rising. Imprisoned in the Tower of London, he was released in 1747 and at some point became a British government double agent. His reasons are still disputed but Scottish historian Andrew Lang confirmed his identity as 'Pickle the Spy' in 1897.