Lawlor, Henry Cairnes (1870–1943), businessman and archaeologist, was born 16 April 1870 in Ballymena, Co. Antrim, youngest child among eight sons and four daughters of John Hilliard Lawlor (murdered 31 May 1889), manager of the local Provincial Bank of Ireland, and his wife, Catherine, daughter of Lt-col. John Elliot Cairnes, KH, of Savile Lodge, Co. Tyrone. Henry's brother, Hugh Jackson Lawlor (qv), became professor of ecclesiastical history at TCD and dean of St Patrick's cathedral, Dublin. Henry attended Connor Diocesan School, Ballymena, and Galway Grammar School, where he developed the passion for history and archaeology that subsequently divided his life's work between study of Ulster heritage and W. R. Young & Co. Ltd, the Belfast spinning mill of which he was director and later chairman.
As an amateur, but by no means dilettante, archaeologist during the transition from antiquarianism to scientific understanding of field monuments and their associated finds, Lawlor was a pathfinder in the development of a professional system of survey, excavation, and reporting which, though inaccurate by later standards, anticipated a modern code of practice. His instinct for Irish prehistoric chronology was impressive, though limited by a general absence of reference material other than an evolving stone-, bronze-, and iron-age framework. He also relied largely on theory that linked Irish prehistory with near-eastern cultures such as Egypt, and considered that Ulster was first colonised for its supply of flint.
One of his earliest published works was A history of the family of Cairnes or Cairns, and its connections (1906), a genealogical study of his mother's family, the Cairneses, especially the Co. Tyrone branch (which included the lord chancellor of England Hugh McCalmont Cairns (qv)). Throughout his life he published extensively in newspapers and journals, particularly the Ulster Journal of Archaeology, of whose editorial board he was a member. Both a member of the RIA (of which his brother Hugh was secretary 1919–30) from 1916, and of the Belfast Natural History & Philosophical Society, he was founding secretary (7 November 1917) of the latter's archaeological section. This section had been created following Lawlor's excavation of the Giant's Ring at Ballynahatty townland in Co. Down, on the southern outskirts of Belfast. Possibly a henge with a passage tomb (cromlech) near its centre, this circular enclosure was a prime example of Lawlor's relatively systematic analysis of a site, its monuments and finds. He also described the unusual ancient practice of building up the outer bank with earth scooped from the interior rather than the surrounding landscape. His published report in the society's Proceedings of 8 January 1918 emphasised the guardianship role of the board of works at proposal and excavation stages, with all finds submitted to the Belfast Museum. In his forensic view of archaeology he observed soil patterns and crop marks to indicate land use and vestigial features, an improvement, however limited, on the destructive eagerness of earlier excavators. Annually, he produced papers on diverse themes of Ulster archaeology. In time his careful, if imperfect, approach would directly influence protective legislation.
Lawlor published Dunluce castle and the Route (1919), a popular illustrated history of outstanding features of the north Antrim coast, with events as recent as an offshore naval encounter in May 1918, and The monastery of St Mochaoi of Nendrum (1925), an excavation in Strangford Lough, Co. Down, featuring a remote and largely forgotten ecclesiastical site. He published his BBC lectures as a highly regarded standard source, Ulster: its archaeology and antiquities (1928). In 1933–4 he was president of the Belfast Natural History & Philosophical Society. Towards the end of his life his writing focused on genealogies of families in Ulster industry. On the administrative side, he was active in drawing up the Ancient Monuments Act, Northern Ireland (1926; amended 1937), and was a member of the ancient monuments advisory council and an adviser on the 1940 survey. In addition, he was involved in the preservation of Dunluce and Carrickfergus castles, among others. To recognise his contribution to archaeology, QUB conferred him with an honorary MA degree. Henry Cairnes Lawlor died 4 September 1943 and was buried in Glenarm.
He married (1893) Beatrice Kathleen (‘Kate’) (d. 1945), youngest daughter of Alexander McDonald, agent for the Antrim estates at Glenarm, and Elizabeth McDonald (née Fawkner). They lived at Killyfaddy, Windsor Avenue, Belfast, and had three daughters and two sons.