St Leger was born in Queenstown, Eastern Cape, South Africa, in 1867 to Frederick York St Leger, the Anglicanrector of Queenstown, headmaster of St. Andrew's College, Grahamstown, and later the founder of the Cape Times. Stratford St Leger received his early schooling at Tonbridge School in England and completed his education at Diocesan College in Rondebosch, Cape Town. He had captained Bishops at cricket and rugby union, after he had completed his schooling he was commissioned into the Royal Irish Regiment in 1890 and during his first nine years of peacetime soldiering he played much cricket for the Army team. In 1895 he married Louisa Anne Galwey and had one daughter, Moira Murdoch of Milnerton, Cape.
St. Leger learned drawing and painting at the schools he attended. During his military campaigns he carried sketch-books in his haversack at all times; he made rough pencil sketches when the opportunity was available and would later work them into final drawings or water colours. His artwork was being published in the London magazineBlack and White by the middle of 1900. His only published book came out in London under the title of War Sketches in Colour in November 1903. In addition to being a detailed account of the experiences of the 1st Mounted it contained full-page reproductions of sixty-six of his sketches in water colour and pen and ink, plus ninety-seven line drawings and five section maps. St. Leger mounted an exhibition of his work at gallery in Bruton Street, Mayfair in May and June 1904 and consisted of fifty water colours with fifteen large and a great many smaller pen and ink drawings.
At the outbreak of the First World War, St. Leger rejoined the Royal Irish and as part of the British Expeditionary Force crossed the English Channel and proceeded to the front. The Royal Irish positions between Mons and Ypres were overrun by a German attack in October 1914, in which many of the regiment were killed or captured. St. Leger was cut off from his unit. He made contact with eight other soldiers from several different regiments in a similar plight. They decided to try to make their way through the German lines. They had no maps and relied on his compass and the stars for direction. The party marched only at night, lying up during the day. Eventually they reached safety in the Belgian lines at Oudenarde and returned to England. St. Leger was awarded the Distinguished Service Order and at the end of the war the Companion of the Order of St Michael and St George, and was posted as Assistant Adjutant General at the War Office. He retired in 1922 and was gazetted full colonel two years later. St. Leger died at Hove in Sussex on 12 October 1935.
