English: Arthur Melland Asquith (1883-1939) was the third of the four sons of Herbert Henry Asquith (British Prime Minister, 1908-1916) and his first wife Helen née Melland. Known always as 'Oc', Arthur was educated at Winchester School and Balliol College, Oxford. His first job was in the newly-created Colonial Service in Sudan. After Lord Kitchener had defeated the Mahdi forces of Abdullah Ibn-Mohammed in the Battle of Omdurman in 1898, Sudan became an Anglo-Egyption protectorate but, from 1901 until 1956, it was effectively administered as a British colony. Oc learned Arabic and fell in love with the country returning there often in later life. After his time in Sudan, Oc joined a commercial firm that had South American connections and visited Argentina a few times.

When hostilities broke out in 1914, Oc joined up. He spent most of the war serving as an officer in the 'Hood', a battallian of the 63rd (Royal Naval) Division. The division was a strange hybrid of Navy and Army created by Winston Churchill when he was First Lord of the Admiralty. The rankings were naval – and beards were allowed – but the division was essentially part of the Army. Oc was a competent, brave and compassionate soldier and was awarded three DSO's>. He was wounded four times. The last of them was the result of a shot in the ankle sustained in December 1917 at Dendermonde, near Antwerp, in the wake of the Second Battle of Passchendaele. As a result his lower leg had to be amputated in January 1918. By then he had attained the rank of Brigadier-General but the loss of a leg obliged him to retire from the service. In April that year he married Betty Manners a daughter of John Manners-Sutton, 3rd Baron Manners. Oc and Betty had three daughters and, after the War, Oc resumed his business career. Often his work took him to South America and North Africa and he was sometimes accompanied by Betty. Oc died aged 56 of Hodgkin's Disease in 1939 but Betty lived until 1962.

HH Asquith had three other sons and one daughter while married to Helen. Oc's younger sister, Violet, married Maurice Bonham Carter in 1915. In 1917 Maurice was knighted and Violet accordingly became Lady Violet Bonham-Carter. In 1953 she was invested as a Dame Commander of the British Empire and, four years after Maurice's death in 1960, she was created a life peer with the title of Baroness Asquith. She died in 1969.

Oc's brothers also had distinguished careers. After a ten-year spell as a barrister, Raymond joined the army at the outbreak of war, was shot in 1916 at the Battle of Flers-Courcelette and died soon after. Herbert was a minor poet and Cyril was a barrister, judge and law lord. When Churchill returned to power in 1951 it's said that he offered Cyril the post of Lord Chancellor saying 'I had an Asquith in my first cabinet and I want one in my last'. But, by then, Cyril was too ill to accept. He died three years later.

Three years after Helen's death in 1891, Oc's father married Margot Tennant. Two further children followed: Elizabeth and Anthony. Anthony Asquith became a leading film director whose many films included 'The Winslow Boy' (1948), 'The Browning Version' (1951) and 'The Yellow Rolls Royce' (1964) – all joint enterprises with the dramatist Terence Rattigan.

HH Asquith was unique amongst prime ministers in having so many talented children.

Sources: Wikipedia and 'The Asquiths' by Colin Clifford (2002).

Where Oc sat for the painting is unknown but it seems appropriate to register the image as Beaumont Street, London, where the King Edward VII Hospital for officers is located. That was where Oc went to have his lower leg amputated after he retired from the Army.