Edward III. erected the earldom of Cornwall into a dukedom, and Parliament settled it in perpetuity upon the sovereign's eldest son, the Castle and Honour of Wallingford being one of the possessions by which the princely dignity was to be supported. Thus the Black Prince became its lord for forty years. After his marriage with Joan, the Fair Maid of Kent, in 1361, this was their most frequent place of residence. Here also the princess remained during the nine years of her widowhood, and here she died, and probably was buried, in 1385. Meanwhile the Black Death had visited the town in 1343; the population had been greatly diminished; several of the fourteen churches had been closed, never to be re-opened; the prosperity and attractiveness of the place was gone, and the Castle was no longer chosen as a favourite residence of royalty. But when it reverted to the crown at the death of the Princess, it was kept up as a military fortress of the first rank, under a constable appointed by the king, and its prominence in history was scarcely lessened. John Beaufort, the son of John of Gaunt, became constable in 1397, and two years later Thomas Chaucer was appointed. He was the reputed son, probably the step-son, of Geoffrey Chaucer the poet, and was almost certainly, like his predecessor, of royal but illegitimate parentage. Under his custody, the youthful Queen Isabella of Valois, the affianced bride of Richard II., was protected at the time of Bolingbroke's invasion, until Richard became a prisoner and the Castle surrendered to the usurper, when the child-queen was carried from one place to another, and at last, in her fourteenth year, returned as a widow to her home in France. A letter of the new King, Henry IV., to his council, relating to Queen Isabella's departure, is dated from Wallingford in 1402. Chaucer was still the constable when the Castle and Honour were settled by King Henry V. upon his bride, Katherine of Valois, at their marriage in 1420. Two years later, the infant King Henry VI. succeeded to his throne, and in 1428, when he was taken from his mother's care, the Castle of Wallingford was assigned to him as one of his summer residences, under the guardianship of the Earl of Warwick. Chaucer died in 1434, and William de la Pole, Earl of Suffolk, his son-in-law, appears to have succeeded him as constable of the Castle. Here Suffolk had under his charge an important captive, Owen Tudor, an esquire of the body to the king, as he had been previously to Henry V. with whom he had fought at Agincourt; and here in his dungeon a secret marriage is said to have taken place between Tudor and the Dowager Queen Katherine, who had long been attached to him, the ceremony being performed by a priest who was his fellow-prisoner, while a servant who attended him was the only witness. Suffolk, now raised to a dukedom, was accused by the populace of betraying his country to the French and preparing to fortify Wallingford on their behalf; and