Denbigh Castle Denbigh Castle ( ) was a fortress built following the 13th - century conquest of Wales by Edward I . The castle , which stands on a rocky promontory above the Welsh market town of Denbigh , Denbighshire , was built upon an earlier Welsh stronghold . It was defended by a unique triple - towered gateway . A planned town ( " bastide " ) was laid out at the same time as the castle . The Anglo - Norman borough was an attempt by Edward I to pacify the Welsh . Construction . Denbigh Castle , which was built during two phases , was based on designs attributed to Master James of St George . In the first period , commencing 1282 , parts of the outer ward were constructed . These outer defences included the southern and western walls and the eastern towers . Later work on the inner ward began including parts of the curtain wall and the castle ' s main gatehouse . The borough ' s new town walls were also began during this period . But in 1294 Denbigh was attacked and taken during the revolt of Madog ap Llywelyn halting the work on the incomplete town and castle . Following its recapture a year later , Henry de Lacy substantially revised the plans in the second phase of building work . This time the inner ward ' s curtain wall were refortified with thicker and higher walls . The main gatehouse was heavily buttressed with a three octagonal towers and a drawbridge : two towers faced outwards and a third interior tower , ( the Badnes Tower ) , inside the main gateway . This three - towered triangular gatehouse now created a heavily defended passageway that had murder - holes , portcullis es in series , two wooden doors , and enfilading arrowslit s . One gatehouse tower contained the porter ' s lodgings while the other served as the prison . During the same period , the Great hall and the eastern domestic ranges including the kitchen tower , the pantry and the postern gate were completed . When the town walls were enlarged , the eastern section was defended by several large D - shaped towers such as the Countess Tower and Goblin Tower . De Lacy died in 1311 before building work ceased on the town and castle defences . The new English borough eventually removed all traces of the original Welsh fortifications . History . The current Denbigh Castle was built on the site of a former Welsh stronghold held by Dafydd ap Gruffydd , the brother of Llywelyn the Last . The Welsh castle originally belonged to Llywelyn the Great . In 1230 , an Abbot from England visited Llywelyn the Great at his new castle in Denbigh . The current stone castle was begun by Henry de Lacy , 3rd Earl of Lincoln in the Lordship of Denbigh given to him by Edward I after the defeat of the last Welsh prince , Dafydd ap Gruffudd in 1282 . The Welsh castle was then torn down and work began on a new English fortress . At the same time , De Lacy was also granted a Royal Charter to create a new English borough and town . But in 1294 , the incomplete castle was besieged and captured by Welsh forces during the revolt of Madog ap Llywelyn . During the subsequent siege , an English force under de Lacy was defeated trying to retake the castle . However the revolt collapsed and Denbigh was returned to de Lacy a year later . Building work then resumed . Following some defensive improvements , the castle and walls were substantially complete by 1305 . In the 1290s , Edward I had issued a second Royal Charter as the market town of Denbigh had rapidly expanded beyond the town wall s and its borough boundaries . By 1305 there were titled 183 settlers living outside the town walls and only 52 inside the town ' s defences . The castle and its precincts were being superseded by the area outside the walls which had developed into the town ' s market centre . A Carmelite Friary was also established in the town just outside the town walls . In 1400 , the forces of Owain Glyndŵr attacked Denbigh . The town was badly damaged but the castle resisted a siege and was not captured . During the Wars of the Roses , Jasper Tudor , the Lancastrian Earl of Pembroke , tried twice and failed to take the castle in the 1460s . In the 16th century Robert Dudley , Earl of Leicester , held Denbigh Castle and its Lordship between 1563 until his death in 1588 . During the English Civil War , the castle was repaired by Royalist Colonel William Salesbury of Rug . King Charles I of England stayed there briefly in September 1645 . The following year , the castle endured a six - month siege before finally being forced to surrender to Parliamentarian forces . The castle was then slighted to prevent its further use . For the remainder of the war part of the castle was used as a prison for captured royalists . Following the restoration of Charles II in 1660 , the castle was abandoned and allowed to fall into decay . Present day . The castle is managed by Cadw - the Welsh heritage agency tasked with looking after historic buildings and monuments in Wales .