[1] He fought in the Thirty Years' War under Gustavus Adolphus and was wounded on 17 August 1632 before Maastricht.
When the Irish rebellion broke out in October 1641, the Commons recommended Sir John for a commission in Ireland.
On the outbreak of the Civil War Merrick was appointed Sergeant-Major-General in the Parliamentary Army commanded by the Earl of Essex.
He commanded an infantry regiment Sir John Merrick's Foot, which took part in the Battle of Edgehill.
[1] Merrick died at the age of 75 and was portrayed in Bush church wearing black armour.