George chose the vocation of soldier while only 17. He served with English expeditions to the Continent, and later with Dutch forces - a not uncommon practice for a soldier of fortune in those days. Subsequently, he commanded his own regiment in Ireland after the rebellion began there in 1641 against the English. He was captured by the parliamentary forces and imprisoned for 2 years in England, but because of his reputation as an excellent soldier, little concerned with politics, he was released and accepted command under the Puritan regime. Still later, after Oliver Cromwell defeated the Scots, Cromwell appointed Monck commander in chief of English forces in Scotland. Soon afterward, Monck was recalled by Parliament and given command in the Dutch War of 1652-1654 as a "general of the fleet. " Though without naval experience, he learned quickly, and the trust that Parliament had placed in him was vindicated in his victory over the Dutchman Maarten Tromp on July 29-31, 1652. The most important chapter in Monck's life began with his return in 1653 to Scotland, where, serving as a commander in chief of parliamentary forces, he suppressed royalist counterrisings. After the death of Cromwell in 1658 and the short-lived rule of his ineffective son, Richard, and then rule by the army, men of various political factions turned to Monck, who had remained aloof from politics. He was taciturn by nature, and his views had always remained a mystery, but his loyalty to the regime and to Parliament was unquestioned. Tension mounted as he marched his army south into England. With the utmost caution, he entered London in February 1660. He soon proclaimed the return of Parliament, which had not been permitted to meet for several months and which, it was known, would now ask for the return of the King. His achievement was the bloodless restoration of the monarchy. Monck occupied a prominent naval command once more in the Dutch War of 1665-1667, with rather mixed results. Afterward, he retired more and more from public affairs. He died on January 3, 1670.
It is likely that he was a moderate Presbyterian.
Monck married Anne Radford (née Clarges).