Through his father, he was descended from a brother of Geoffrey de Mowbray, Bishop of Coutances, who was an adviser to William the Conqueror.
Another relative, William de Mowbray, was one of the barons who forced King John to put his seal to Magna Carta in 1215; as a direct descendant, Charles travelled to Washington, DC in 1976 with a parliamentary delegation that presented one of the four copies of the Magna Carta held by the British Museum to the US Congress.
He was educated at Ampleforth College and Christ Church, Oxford, and served as a lieutenant in the Grenadier Guards in the Second World War.
Despite his strong Roman Catholic faith, he took his mother's side when his parents separated in 1961, in a case that drew significant publicity.
His father was labelled "egocentric" and his mother was granted a decree of judicial separation on the grounds of her husband's cruelty.
The family seat at Allerton Park, near Knaresborough in Yorkshire, perhaps the most important Gothic Revival stately home in England, was left in trust until Edward was 30.
Mowbray also served as President and Delegate of the British and Irish Association of the Sacred Military Constantinian Order of St George under the Grand Master, the Duke of Castro between 1975–2000.