He began his career as a Royalist and was taken prisoner during the English Civil War; however, he was then given a command by Parliament and later completed the suppression of the Royalists in Scotland. In the first Anglo-Dutch War he fought three naval battles before returning to Scotland in 1654. He was trusted by Cromwell, but after the Protector’s death he acted to secure the restoration of Charles II in 1660, and he received many honours. Monck was placed in charge of London during the Great Plague (1665) and Fire of London (1666).