Life and work
Horace was born on 18 April 1889 at Croydon, England. His father Joseph Gundry Alexander (1848–1918) was an eminent lawyer, who had worked to suppress the opium trade between India and China. His mother was Josephine Crosfield Alexander. His early schooling was at Bootham School in York, after which he studied at King's College, Cambridge, where he graduated in history in 1912. In 1914 the First World War broke out, and he served as secretary on various anti-war committees. In 1916, as a conscientious objector, he was initially exempted only from combatant military service, but after two levels of appeal he was exempted on condition of teaching, which he took up via General Service with the Friends' Ambulance Unit, holding posts at Sibford School, Warwick School and Cranbrook School, Kent.
He married Olive Graham (1892–1942) on 20 July 1918 and joined the staff of Woodbrooke, a Quaker college in Birmingham, teaching international relations, especially in relation to the League of Nations, from 1919 to 1944. His wife Olive died in 1942, having been confined to a wheelchair for several years. In the same year Alexander joined a section of the World War II Friends Ambulance Unit and went to parts of India threatened by Japan. In 1958 he married Rebecca Bradbeer (née Biddle, 1901–1991), an American Quaker. After ten years they moved to Pennsylvania, United States, where he spent the remaining twenty years of his life. He was also, for its first ten years, a governor of Leighton Park School, a leading Quaker school in England. He died of a gastrointestinal illness at Crosslands, a Quaker retirement community in Kennett Square, Pennsylvania.