Sir John de Mowbray, KG 3rd Duke of Norfolk (12 Sep 1415 – 6 Nov 1461) married Eleanor Bourchier by 1424, while they were both children and he was a ward of her mother's. A dispensation for them to stay married was dated 9 March 1433/4. They had one son, John Mowbray, 4th Duke of Norfolk.
He was knighted in 1426 at the same time as the young King Henry VI.
In March 1436/7 he was appointed Keeper of the East March with Scotland and with Berwick.
In March 1437/8 was was joint leader of the expedition to recapture Calais. The following year he was joint leader of a peace embassy to France.
In 1443 he helped to end riots in Norwich.
On 11 March 1444/5 he was confirmed as Duke of Norfolk.
In 1446 he was granted permission to make a pilgrimage to Rome. He may have made the pilgrimage in 1449.
During the conflicts between Yorkists and Henry VI from 1450 to his death, he seems to have sought to avoid for some years firmly committing himself to one side or the other. In 1450 participants in Jack Cade's rebellion called for him to be one of the King's council. At this time he was in alliance with the Duke of York against the Duke of Somerset, and in 1453 he was involved in Somerset's arrest. Nevertheless in 1452 he supported the king's government against the Duke of York, receiving £200 and a gold cup for this. In 1454 he excused himself on grounds of health when he was invited to join the King's Council under the Duke of Somerset.
He arrived a day too late to take part, on the King's side, in the 1st Battle of St Albans in 1455. Three years later he and his wife were serving Henry III's queen, Margaret of Anjou. He kept out of fighting in the autumn of 1459, and on 11 December 1459 swore an oath of loyalty to Henry VI. But in the 2nd Battle of St Albans (17 February 1461) he abandoned the king. He joined the Yorkists, and was one of those who proclaimed Edward IV king on 3 March 1461. He fought for the Yorkists in the Battle of Towton (29 March 1461). When Edward IV was crowned on 28 June 1461, he served as Earl Marshal.
He died in November 1461 and was buried at Thetford Priory.
↑ 1.01.11.21.18.104.22.168 Oxford Dictionary of National Biography: Mowbray, John, third duke of Norfolk, available online via some libraries
↑ 2.02.12.22.22.214.171.124.7 Richardson, Douglas. Magna Carta Ancestry: A Study in Colonial and Medieval Families, 2011, vol. 3 p.214: MOWBRAY 9
↑ 3.03.13.23.126.96.36.199 Cokayne, G E, Complete Peerage, edited Doubleday, H A and Lord Howard de Walden, vol. 9, St Catherine Press 1936, p.607-8: John Mowbray, Duke of Norfolk
↑ Dallaway, J. (1830). "Pedigree of Mowbray." A history of the western division of the county of Sussex, Volume 2, Part 2, (pp.181). T. Bensley. Google Books
Richardson, Douglas. Royal Ancestry: A Study in Colonial and Medieval Families, 5 vols, ed. Kimball G. Everingham. Salt Lake City: the author, 2013, volume IV. p.195. See also WikiTree's source page for Royal Ancestry.
It may be possible to confirm family relationships with John by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
However, there are no known yDNA test-takers in his direct paternal line.
Mitochondrial DNA test-takers in the direct maternal line: