Denbigh Castle is one of the fortresses that formed King Edward I's "ring of castles", four of which (Caernarfon, Conwy, Harlech and Beaumaris) have been named World Heritage sites. Construction of the castle began in 1282 by Henry de Lacy, one of Edward I's chief commanders. It was not the first stronghold to occupy this strategic site: it was built over the stronghold of Dafydd ap Gruffudd, the Welsh leader crushed by Edward in 1282. During the Civil War (1642-1649), the then decaying castle was repaired by Colonel William Salesbury. In 1646 the castle endured a nine month siege. When Denbigh finally surrendered on 26 October 1646, it was only after the King had personally ordered Salesbury to do so.