Denbigh stands on a limestone height crowned by a castle, Din-bach, the Little Fortress or Castle. But that is not the popular derivation of the name. A monster, the Bych, occupied a cave in the face of the rock, now almost choked up. Thence it issued to ravage the country, but was killed by Syr Sion y Bodiau, the double-thumbed son of Catherine of Berain. But as Sir John Salusbury lived in the reign of Elizabeth, it is clear that some ancient myth has attached itself to him which belonged originally to a primeval hero. The first certain account of the castle is at the time of the final conquest of the Principality. King Henry III. granted the custody of it to Dafydd ab Gruffydd, that treacherous and unprincipled prince who was the brother of Llewelyn, the last Prince of Wales of the native stock. After the execution of David at Shrewsbury in 1283 the fortress was granted to Henry de Lacy, Earl of Lincoln, who erected the present castle.

Old Denbigh occupied the area in front of the castle, but this part was abandoned about the reign of Elizabeth for New Denbigh, built at the foot of the hill, either because there was lack of water on the summit of the rock, or because the steepness of the ascent rendered a residence more convenient lower down. Now the space within the walls is unoccupied save by the little church of S. Hilary, and the ruins of a cathedral begun by the Earl of Leicester, who proposed to transfer thither the seat of the bishop from S. Asaph. But it was not completed. This is to be regretted, as it would have been a most curious specimen of Gothic in its last stage of decay. We have plenty of examples of domestic architecture of the period, and very delightful they are, but of ecclesiastical buildings none. It was a period of church gutting and pulling down, and not of erection and decoration. Henry de Lacy was engaged on building the castle when a fatal accident disheartened him, and he left the work incomplete. He had erected a tower, now called that of the Goblin, over a well with an unfailing spring in it, that was to supply the castle. His son Edmund, a boy of fifteen, was playing in the tower, scrambling among the scaffolding, when he lost his footing, fell to the bottom, and was killed.

The water has now been drawn off to a bath-house outside, at the foot of the rock, and was at one time supposed to possess curative properties.

The dead boy’s spirit is thought still to haunt the tower, and his white face to be seen peeping out of the ruined windows.

Henry de Lacy’s daughter Alice was married to Thomas Plantagenet, Earl of Lancaster, and he by right of his wife became Earl of Denbigh. Edward of Carnarvon had received his father’s instructions before Edward I. died. Of these the principal were: that he should persist in the conquest of Scotland, and should not recall his favourite Piers de Gaveston. These commands were violated by the young King. His first act was to send for Gaveston, and to confer on him the royal earldom of Cornwall; and when, at the coronation of Edward, Gaveston was given precedence over all the great nobles of the realm, their wrath knew no bounds. Three days after the ceremony they called upon the King to dismiss his favourite. Edward was obliged to give way, and Gaveston to swear that he would never return. The Pope, however, released the favourite from his oath, and shortly after Edward recalled him. The Earl of Lancaster and Denbigh refused to attend the next parliament convoked by the King, and the barons, flying to arms, captured Gaveston at Scarborough, and by order of Thomas of Lancaster cut off his head.

The news affected the King with passionate grief, to which was quickly added a fierce desire for revenge.

Some time after the death of Gaveston, Edward found a new favourite, Hugh le Despenser, whose harsh attempt to enforce feudal law to his own advantage excited the marchers of Wales to arms against him. They were joined by Thomas of Lancaster, but he was defeated and taken to Pontefract Castle, where he was executed. Upon his death Denbigh was conferred on Hugh le Despenser.

The incapacity and favouritism of Edward occasioned a fresh outbreak, and Hugh le Despenser fell into the hands of the barons, who hanged him after a hasty trial. Then Denbigh Castle passed to another favourite, Roger Mortimer, the paramour of Queen Isabella. He was taken at Nottingham, arraigned in a Parliament summoned at Winchester, and hanged at Tyburn.

It really seemed that Denbigh was doomed to bring ill-luck on its masters. That ill-luck did not end with the hanging of Mortimer.

In 1566 Elizabeth granted it to her favourite, Robert Dudley, Earl of Leicester, whom she created Earl of Denbigh.