What were the three most important things oliver cromwell did?

Oliver Cromwell was a key figure in the English Civil War and the subsequent establishment of the Commonwealth. First, he led the Parliamentarian forces to victory against King Charles I, which resulted in the execution of the king in 1649. Second, Cromwell served as Lord Protector, implementing significant political and social reforms, including promoting religious tolerance and military governance. Lastly, he played a crucial role in the expansion of England's influence through military campaigns in Ireland and Scotland.