Oliver Cromwell, historical personality (New Model Army) with a connection to Wales (Llanishen)
Oliver CromwellLawyer, MP, firebrand, soldier and ultimately Lord Protector of England 1649-58. Abolished the monarchy, privy council, courts of exchequer, admiralty, house of lords. Briefly succeeded by his son Richard.
Connection: Real name Oliver Williams. Son of Sir Henry Cromwell and grandson of Richard Williams, who first used the name Cromwell, Thomas Cromwell being his uncle and patron. Great grandson of Morgan Williams of Llanishen, a brewer and innkeeper.
Infamously commanded Charles's armies on their campaigns in Ireland and Scotland, though much propagandized by the Stuarts. Ed - I understand he is hated by the Irish for good reason, The Irish campaign would be considered a war crime by modern standards.