Kelly spent the following fourteen years imprisoned in the Tower of London, during which time he published translations of Castlenau's Memoirs of the English Affairs (1724) and Morabin's History of Cicero's Banishment (1725).
[2] On 26 October 1736 Kelly escaped from the Tower with the aid of Jacobite sympathisers, including Fr Myles McDonnell, and made his way to Avignon.
At Versailles, Kelly clashed with and undermined the Jacobite agents Francis Sempill and Daniel O'Brien, who had been appointed by Charles' father, James.
Following the Jacobite victory at the Battle of Prestonpans in September, the Prince sent Kelly back to France with news of the rising's success in the hope of gaining further support.
He entered into relative obscurity, returning briefly in 1760 to sow dissension between the increasingly dissolute Charles and his lover Clementina Walkinshaw.
[6] William MacGregor of Balhaldy wrote of Kelly to James Edgar on 31 May 1747, "trick, falsehood, deceit, and imposition, [are] joined to those qualities that make up a sycophant".