Educated at Ampleforth College and Christ Church, Oxford,[1] Miles Fitzalan-Howard was commissioned as a second lieutenant in the Territorial Army as a university candidate on 3 July 1936.

[5] In April 1944, as a temporary major during the Second World War, he was awarded the Military Cross for reconnaissance of mined roads.

[8] Promoted to lieutenant-colonel on 28 February 1955,[9] he was appointed Chief of the British mission to the Soviet forces in Germany in 1957, and received a promotion to colonel on 24 April 1958[10] He was appointed a Commander of the Order of the British Empire (CBE), Military Division, in the 1960 New Year Honours.

[15] After relinquishing his command on 5 November 1965, he became Director of Management and Support Intelligence at the Ministry of Defence on 6 January 1966[16] Appointed a Companion of the Order of the Bath (CB) in the 1966 Queen's Birthday Honours,[17] he was appointed Director of Service Intelligence at the Ministry of Defence on 29 July.

[1] He became, by virtue of this office, the hereditary judge of the Court of Chivalry and head of the College of Arms, responsible for heraldry in England and Wales as well as other parts of the Commonwealth of Nations such as Australia and New Zealand.

One of eight children (all of whose first names started with the letter "M"), the Duke married Anne Mary Teresa Constable-Maxwell in 1949.