Robertson, Lawrence Alexander Durdin- (1920–94), Church of Ireland clergyman and priest of Isis, was born in London on 6 May 1920, the elder son of Manning Robertson (qv) and his wife Nora (née Parsons), a connexion of the earl of Rosse. According to Burke, the earliest known Robertson of the line was John, lord of the free barony of Strathloch and known as Lord Strathloch, who lived in Scotland in the early 16th century; descendants lived in Orkney; the Irish connection was made in 1880 when Herbert Robertson (1849–1916), a barrister practising in England and later Tory MP for South Hackney, married Helen Alexandrina Melian Durdin (1855–1933), eldest daughter and heiress of Alexander Durdin (1821–92) of Huntington Castle, Clonegall, Co. Carlow. Lawrence Robertson was educated in Dublin at Baymount, Sandford Park and St Columba's College before entering TCD, where, however, his studies were interrupted by the second world war, during which he served in the Irish army anti-aircraft battalion (1940) and was employed as a civilian at the British Admiralty Research Laboratory, Bath (1942–5). Having resumed his studies he graduated BA (1946) and was ordained in the Church of Ireland (1948). He served in Ireland as a curate in the Maryborough Union (1948–51), then in Aghowle and Mullinacuff, Co. Wicklow (1951–2), before moving to England to be rector of East Bilney with Beatley in Norfolk (1952–7).
In 1952 Robertson had a revelation of the feminine aspect of God. Eventually he returned to the family home, Huntington Castle, to engage in farming, develop an interest in other religions and, with his sister Olivia and wife Pamela, to found the Fellowship of Isis (1976). Dedicated to the worship of goddesses of all kinds, it eventually attracted several thousand followers. In 1972 he was ordained a priest of Isis and by deed poll assumed the additional prefix surname Durdin. The castle became a centre for the cult of goddesses; its basement was converted into a temple of Isis, complete with twelve shrines and five chapels (each consecrated to a different goddess). To perform the rites of Isis, Durdin-Robertson would don blue robes, a crook and a tall blue pharaonic headdress. Using the imprint Cesara Publications, he published a score of books, pamphlets and manuals including The cult of the goddess (1975), The goddesses of Chaldaea, Syria and Egypt (1975), The goddesses of India, Tibet, China and Japan (1976) and God the mother (1984?). Olivia Robertson (b. 1917), the younger of Manning Robertson's two daughters, threw herself into psychic and spiritualist studies at an early age and in 1946 had a revelation of the femininity of God; an accomplished author in her own right, she achieved great success with St Malachy's Court (1946), which drew from her experiences working at Dublin city corporation playgrounds, and Field of the stranger (1948), the English Book Society's choice of the year; she went on to write six more books, the latest The call of Isis (1975). She was an important influence over her brother Lawrence and became a priestess of Isis.
The other important influence was his wife Pamela Mary, the extrovert only daughter of Major Maurice Edward Barclay of Brent Pelham Hall, Buntingford, Hertfordshire, a master-of-foxhounds. The couple married on 14 January 1949 and had a son and three daughters. On her death (1987) Durdin-Robertson lost, he believed, his psychic powers. Always known to his family as Derry (after the river flowing through Huntington), he was in his last years known as Lord Strathloch, the title of 21st Baron Robertson of Strathloch having been recognised at the Office of Arms, Dublin (7 May 1978); he was a gaunt figure, quiet, pensive and unconventional – he always wore a Scottish Robertson bonnet at table. Lawrence Durdin-Robertson died 4 August 1994 and received a Christian burial as well as an Isian funeral. His younger brother was Esmonde Manning Robertson (d. 1987).