joined his brother John in an expedition to Brittany. After crossing the Channel they laid siege to St. Malo. Du Guesclin marched to its rescue, but would not be induced to risk an engagement, though Edmund endeavoured to provoke him to one. Eventually the English went home without effecting anything.
Early in May 1380 a Portuguese embassy came to appeal for aid against the king of Castile, and as a result Edmund was despatched at the head of five hundred lances and as many archers. Accompanied by his wife and son, he sailed from Plymouth in July 1381, having hastened his departure, so it is said, for fear the rising under Wat Tyler should prevent his going (Froissart, viii. 29, ed. Buchon). Sir Matthew de Gournay [q. v.], the Canon of Robertsart, and others, took part in the expedition. The English reached Lisbon after a stormy voyage of three weeks' duration. In accordance with a treaty already concluded, Edmund's young son Edward was married to Beatrice, the daughter of King Ferdinand of Portugal. Edmund then went to Estremoz, but most of the English were under the Canon of Robertsart at Villa Viciosa, whence during the winter they made an attack on Higueras against the wishes of the king of Portugal. In April 1382 the English, weary of inaction, remonstrated with Edmund, who could only reply that he must wait for his brother John. Shortly afterwards the English made a fresh raid, and captured Elvas and Zafra. Thereupon Edmund came to Villa Viciosa; but the English, now thoroughly discontented, threatened to turn free-lances, and fight on their own account, unless some action was taken. Under pressure from his followers, Edmund then went to Lisbon to remonstrate with the king, and obtained from him a promise to take the field. But Ferdinand was now, as previously, intriguing with the Spaniards, and presently, before any fighting took place, made peace without reference to his English allies. Edmund would have attacked the king of Portugal if he had felt strong enough, but as it was he had no choice except to return to England, where he arrived in October 1382 (Fœdera, iv. 156, Record ed.). The king of Portugal soon after remarried his daughter to the infant of Castile. Nevertheless, Edmund did not give up his hopes of securing a footing in that country, and in 1384 opposed the Scottish war for fear that it would interfere with his projects. In the summer of 1385 he took part in the king's expedition to Scotland, and was rewarded for his services by a grant of 1,000l. (ib. vii. 474, 482). On 6 Aug. of the same year he was created Duke of York (Rot. Parl. iii. 205). In the troubles of his nephew's reign, Edmund, who cared little for state affairs, only played a small part. He was content to follow the lead of his brother John, duke of Lancaster, or in his absence that of Thomas, duke of Gloucester. In 1386 he was at Dover, waiting to repel a threatened French invasion, and he was also one of the fourteen commissioners appointed by parliament to receive the crown revenues (ib. iii. 221). At this time Edmund supported Gloucester in his opposition to the king's favourite, Robert de Vere, and was with Gloucester when he defeated De Vere near Oxford in 1387 and when he met the king at Brentford. Three years later his elder brother was back in England, and Edmund now followed his guidance in seeking for peace with France, against the wishes of Gloucester. Consequently, in March 1391, the dukes of Lancaster and York went to Amiens to conduct the negotiations for peace.
When Richard went to Ireland in September 1394, Edmund was appointed regent, and in this capacity held the parliament of January 1395 (ib. iii. 330). In September 1396 he was again regent during the king's absence on his visit to France to wed the Princess Isabella. During these years Edmund was under the guidance of his elder brother. Thomas of Gloucester, however, as Froissart says, made no account of him during his intrigues, and Edmund took no part in the events which attended his younger brother's death in 1397. When Richard went to Ireland in March 1399, Edmund was for the third time made regent. Personally, no doubt, he was loyal to his nephew, but it was his lack of vigour which made the success of Henry of Lancaster so easy. Edmund, indeed, prepared to oppose Lancaster, but finding little support, shortly went over to his side, and accompanied him in his progress to Bristol. Afterwards Edmund came forward for once as a statesman, and he has the credit of having suggested that Richard should be induced to execute a formal resignation of the crown previous to the meeting of parliament. After the coronation of the new king Edmund retired from the court, and the only other incident of interest in his life was his discovery of his son Rutland's plot in January 1400. He died at Langley on 1 Aug. 1402, and was buried in the church of the Dominicans there by the side of his first wife. His tomb was removed to King's Langley Church about 1574, and since 1877 has stood in a memorial chapel in the north aisle.
Edmund was the least remarkable of his father's sons. He was an easy-going man of