Pontefract Castle is a ruin in the town of Pontefract in West Yorkshire. It was the site of a series of famous sieges during the English Civil War. Royalists controlled Pontefract Castle at the start of the war and the first of three sieges began in December 1644, and continued until the following March when Marmaduke Langdale arrived with Royalist reinforcements and the Parliamentarian army retreated. During the siege, mining and artillery caused damage and the Piper Tower collapsed as a result. The second siege began on 21 March 1645, shortly after the end of the first siege, and the garrison surrendered in July after hearing the news of Charles I's defeat at the Battle of Naseby. Parliament garrisoned the castle until June 1648 when Royalists sneaked back into the castle and took control. 

Oliver Cromwell led the final siege of Pontefract Castle in November 1648. Charles I was executed in January, and Pontefract's garrison came to an agreement;  Colonel Morrice handed over the castle to Major General John Lambert on 24 March 1649. Following requests from the townspeople, the grand jury at York, and Major General Lambert, Parliament gave orders that Pontefract Castle should be "totally demolished & levelled to the ground". (wikipedia article).

Coins were issued in the name of Charles I before his execution, and in the name of Charles II after the execution. 

 Reconstruction of Pontefract Castle, CC BY SA,

 Initial photograph by Rept0n1x, cleaned up and adapted by Hchc2009.