Sir John Grey, Count of Tancarville born c.1384–1421), soldier and diplomat

Grey may be the John Grey valletus domini (‘attendant of his lord’) in the service of Sir Henry Percy (Hotspur) at the castle of Denbigh in April 1403. Along with Richard Ledes he challenged two Scotsmen to six courses on horseback at Carlisle in June 1404. It is likely that he was associated with the household of Henry, Prince of Wales, and that he served in the Welsh wars, as did his eldest brother. In March 1408, as esquire, Grey was granted an annuity of 20 marks by the prince, and on 14th August 1409 Henry IV granted a further annuity of 40 marks out of the issues of Northumberland for his services to king and prince. Grey served on the expedition sent under the prince's orders in September 1411 to assist the duke of Burgundy. By September 1413 he was a king's knight, and received further royal largess in the early years of the new reign.

At the landing of the campaign of 1415 Grey was one of a group of knights detailed to reconnoitre the country towards Harfleur; another, Sir Gilbert Umfraville, had also served on the expedition of 1411. Grey took part in the siege of Harfleur and the battle of Agincourt, where he captured the Count d'Eu. On 8th August 1415 he was granted custody of the lands held in fee tail by his eldest brother, Sir Thomas Grey of Heaton, during the minority of the latter's heir, and himself received the lands that his brother had held in fee simple. In May 1416, by now a knight-banneret, he indented to serve in the naval expedition that the king intended to lead in person but that subsequently sailed under John, Duke of Bedford, and defeated the French off Harfleur on 15th August. He crossed on the campaign of 1417 and was one of Henry's most trusted captains in the conquest of Normandy. He was present at the siege of Caen and was appointed to the captaincy of the castle and town of Mortagne (Orne) on 31st October 1417. He campaigned in Lower Normandy under the duke of Gloucester in the spring and summer of 1418. At the siege of Rouen he was positioned on the Mont-St Michel; John Page's poem about the siege speaks of him as ‘a comely knyght’. When Rouen surrendered in January 1419 Grey was given power to receive into the king's hands all castles in Normandy and to issue letters of safe conduct to all who wished to do homage. The level of royal trust he enjoyed is also revealed by appointments to diplomatic missions between October 1418 and April 1419. When Mantes surrendered in February 1419 he was appointed to its captaincy, a post he held until August, subsequently participating in Henry V's advance towards Paris. In November 1419 he was directed to receive inhabitants of the châtellenies of St Germain, Montjoy, and Poissy into the king's obedience, and was in the same month made a knight of the Garter. On 20th January 1420 Grey was appointed to the important captaincy of Harfleur, an office he held until his death. He served at the siege of Melun in July 1420 and on the expedition of Thomas, duke of Clarence, into Maine and Anjou where he met his death, along with Clarence and several other English captains, at the battle of Baugé on 22 March 1421. His closeness to the king had brought him rich rewards in Normandy. On 20 November 1417 he had been granted the castle and lordship of Tilly-sur-Seulles (Calvados) in tail male, and on 31st January 1419 the Comté of Tancarville also in tail male, along with a house in Rouen; a year later he had received the custody of the lands of an important Norman prisoner as well as a house in Caen.

Grey had married by 1419 Joanna Cherleton, elder daughter, and coheir with her younger sister Jocosa, of Sir Edward Charlton of Powys  Their son, Henry, also count of Tancarville, was described in his father's inquisition post mortem in April 1421 as aged a year and a half or more. The comté of Tancarville was lost in the French reconquest of Normandy. Henry's son, Sir Richard Grey, was styled Lord Grey of Powys. The earldom of Tancarville was created de novo in June 1695 for Edward Grey, a descendant in the female line of Thomas Grey of Heaton, Sir John Grey's eldest brother.

John and Joan had one son

Sir Henry Grey born c. 1420

His widow, Joan, died on 17th September 1425.