George Monck was a professional soldier whose changing service connected the Civil Wars with the Restoration of the monarchy. After fighting in the Netherlands, he served Charles I in Ireland and England. Captured at Nantwich in 1644, he spent time in parliamentary custody before accepting service under Parliament. His subsequent commands in Ireland and Scotland made him an important officer in the regime that emerged from the king's defeat.

Under Oliver Cromwell he helped subdue Scotland and eventually commanded the army there. He also served at sea as a general-at-sea during the First Anglo-Dutch War, participating in the fleet's major operations in 1653. The regiment he raised in 1650 later became the Coldstream Guards. His reputation rested on discipline, administrative competence and the loyalty of his troops, resources that became politically decisive after Cromwell's death in 1658.

Monck initially supported Richard Cromwell, but the collapse of the Protectorate and struggles among army factions brought him south from Scotland in early 1660. In London he promoted the restoration of parliamentary authority and the return of members previously excluded from the Commons. He cautiously managed contacts with royalists while avoiding a premature declaration that might have divided his soldiers. Elections to the Convention Parliament opened the way for Charles II's return.

His recommendations helped shape the Declaration of Breda, and the restored king rewarded him with the dukedom of Albemarle and high military office. Monck assisted in reorganizing and reducing the army while preserving a force loyal to the crown. During the Second Anglo-Dutch War he again commanded at sea, including the Four Days' Battle in 1666. His career ended within the restored monarchy he had helped make possible. It shows how control of a disciplined army could enable a political settlement, even when the commander had previously served opposing sides.