Despite his loyalties to the King, who had fled to Oxford on the outbreak of the
English Civil War, Crisp remained in
Roundhead-controlled London. However he was questioned by the House of Commons in January 1643 about £3,700, which an intercepted letter revealed as owed to him 'for secrett service done for his Majestie'. He promptly slipped away to Oxford, where he was warmly welcomed by the King, but his homes in Hammersmith (
Brandenburgh House) and
Lime Street were ransacked. Crisp was forced by Parliament to surrender his patents for making and vending beads and for slave trading from Guinea to the West Indies. An order relating to a debt owed by Sir Nicholas Crisp to the Navy was laid before the
House of Lords in December 1643. The
House of Commons of England had ordered that Crisp's share in the
Guinea Company, his trading venture to Africa, should be used to cover this debt. The arrival of gold from this adventure now prompted the House of Lords to confirm that Crisp's share in this should be used to pay off the debt. Crisp 's supported the King in a number of ways throughout the Civil War. He was at the centre of a plan in March 1643 to head a force to take over London, but the idea failed. A letter to him from Sir
Thomas Ogle was intercepted and published. He was also frustrated in his attempts to raise an infantry regiment of 1,500 later that year. However, on 6 May 1644, he was commissioned to equip 15 warships at his own and his partner's expense and granted a tenth of any prizes taken by them. Operating from west country ports, he ferried troops from
Ireland and played an important role in shipping
tin and
wool to the continent. He would also bring back arms and ammunition as a return cargo, and ultimately held the important position of deputy
controller-general of posts. His allegiance to the crown was steadfast, even after Charles I was executed in 1649 and he was forced to flee to France like many others. Family connections allowed him to return but his politics had not changed in the least and in the run up to the Restoration, Crisp performed secret services and raised money for exiled Charles II. He was among those London Royalists who signed the declaration in support of
General Monk to restore the Stuart monarchy. He was also involved in clandestine support for royalist conspiracies, such as the abortive plot of 1650 to land forces from the Scillies on the Cornish coast. In May 1660 Crisp was one of the committee sent to meet
King Charles II at
Breda as he returned to England to take to the throne his father had vacated. ==Later life==