The last independent prince of Wales died on September 20, 1415. Glendower served the future Henry IV of England while a young man. Glendower led a Welsh revolt, beginning in 1400/01, which began when neighbor Reginald Grey, 3rd Baron Grey de Ruthyn, failed to notify Glendower of Henry's call to his Scottish campaign in 1400, then disingenuously charged Glendower with treason. By the time Henry learned of the rebellion, he had difficulty quelling it. Glendower gained control over most of Wales by 1405, in part due to an alliance with Henry Percy and Edmund Mortimer. Welsh control lasted until 1408, when Henry's son, the future Henry V captured Aberystwith. The circumstances of Glendower's death remain uncertain to this day.
Walter Scott references Owen Glendower, and the setting in 1400, in a publication titled "Scotland", by Sir Walter Scott, Dionysius Lardner, and Mayo Williamson Hazeltine:
'In 1400, Henry therefore summoned the whole military force of England to meet him at York, and published an arrogant manifesto, in which he vindicated the antiquated claim of supremacy, which had been so long in abeyance, and, assuming the tone of lord paramount, commanded the Scottish king, with his prelates and nobles, to meet him at Edinburgh and render homage. Of course no one attended upon that summons, excepting the new proselyte March, who met Henry at Newcastle, and was received to the English fealty. But if Henry's boast of subjecting Scotland was a bravado inconsistent with his usual wisdom, his warfare, on the contrary, was marked by a degree of forbearance and moderation too seldom the characteristic of an English invader. Penetrating as far as Edinburgh, he extended his especial protection to the canons of Holyrood, from whom his father, John of Gaunt, had experienced shelter, and in general spared religious houses.
The castle of Edinburgh was gallantly held out by the Duke of Roth say, aided by the skill and experience of his father-in-law, the Earl of Douglas. Albany commanded a large army, which, according to the ancient Scottish policy, hovered at some distance from the English host. The Soots had wisely resolved upon the defensive system of war which had so frequently saved Scotland. But they could not forbear some of the bravado of the time. The Duke of Rothsay wrote to Henry that, to avoid the effusion of Christian blood, he was willing to rest the national quarrel upon the event of a combat of one, two, or three nobles on every side. Henry laughed at this sally of youthful vivacity, and, in answer, expressed his wonder how Rothsay should think of saving Christian blood at the expense of shedding that of the nobility, who, it was to be hoped, were Christians as well as others. Albany also would have his gasconade. He sent a herald to Henry to say that, if he would stay in his position near Edinburgh for six days, he would do battle with him to the extremity. The English king gave his mantle and a chain of gold to the herald, in token that he joyfully accepted the challenge. But Albany had no purpose of keeping his word; and Henry found nothing was to be won by residing in a wasted country to beleaguer an impregnable rock. He raised the siege and retired into England, where the rebellion of Owen Glendower soon after broke out. A truce of twelve months and upward took place between the kingdoms.'