In 1648, at the beginning of the Second Civil War, Pembroke's commander Colonel John Poyer led a Royalist uprising alongside Colonel Powell, Tenby Castle, and Sir Nicholas Kemoys, Chepstow Castle. Oliver Cromwell came to Pembroke on 24 May 1648 and took the castle after a seven-week siege. Its three leaders were found guilty of treason and Cromwell ordered the castle to be destroyed. Townspeople were even encouraged to disassemble the fortress and re-use its stone for their purposes.