In the political struggles that followed victory in the 1642 to 1646 First English Civil War, he was one of the Eleven Members accused by senior Army officers in July 1647 of attempting to destabilise the kingdom.

[2] His father was a close associate of William Coryton, leader of Cornish opposition to the 1627 Forced Loan; a key stage in the struggle between Charles I and Parliament, this led to the institution of Personal Rule in 1629.

[5] In February 1643, Parliamentarians in Cornwall and Devon agreed a local truce with their Royalist opponents, causing outrage in London.

"[7] His uncle John Pym died in December, while Stamford, Parliamentary commander at Stratton, filed charges against Nicholl, claiming blamed for his defeat.

[9] Arrested on 17 August on his way home, he was taken to New Model Army headquarters in Kingston upon Thames, but quietly allowed to escape a few days later.

Parliamentary proceedings to impeach the Eleven Members were suspended when the Second English Civil War began in February, then abandoned in June.

[2] He was appointed High Sheriff of Cornwall in 1657, and provided regular updates to John Thurloe, head of intelligence under the Protectorate.