Oliver Cromwell rose through the ranks of the English military from commanding a single cavalry troop to leading the entire army. After removing King Charles I from power during the English Civil War, Cromwell ruled as Lord Protector of the Commonwealth from 1653-1659. During his conquest of Ireland, Cromwell's forces massacred over 3,500 Irish at the siege of Drogheda and killed 2,000 soldiers and 1,500 civilians at the siege of Wexford, demonstrating his harsh treatment of Catholics and the Irish people during his rule.