During the nineteenth century, geology was perceived by the British Army as a military science, and two geological survey departments outside Great Britain were pioneered by Royal Engineer officers in the rank of captain: J. W. Pringle, J. E. Portlock and Henry James nearly successively in Ireland between 1826 and 1846; H. G. Lyons in Egypt from 1896 to 1898 and then, as a civilian, until 1909. During World War I, the Welsh-born Australian T. W. Edgeworth David and the Canadian R. W. Brock served on attachment to the Royal Engineers in the rank of major, David as the senior of two geologists in appointment as such with the British Army in France and Belgium 1916–1919, Brock in Palestine 1918–1919. (David was rewarded by promotion to lieutenant-colonel ten days before the end of hostilities). During World War II, between 1939 and 1945, W. B. R. King, F. W. Shotton, J. V. Stephens, W. A. Macfadyen, J. L. Farrington and D. R. A. Ponsford plus the South Africans H. F. Frommurze and G. L. Paver (and possibly also H. Digby Roberts) all achieved the rank of major whilst in appointment as geologists serving with British forces, complemented in the Far East by Majors A. J. Haworth and A. N. Thomas supervised by E. J. Bradshaw for the Indian Army. (King was rewarded with promotion to lieutenant-colonel in October 1943, when released from the Army to take up appointment as Woodwardian Professor of Geology at the University of Cambridge). During the remaining twentieth century, N. L. Falcon, D. R. A. Ponsford, A. W. Woodland, A. F. Fox, Frank Moseley, R. M. S. Perrin, S. C. L. Hobden, L. R. M. Cocks and J. C. Eaton became geologist majors in the British reserve army, and five majors were promoted to be geologist lieutenant colonels: T. G. Miller 1964–1967, N. F. Hughes 1967–1970, P. I. Manning 1971–1972, E. P. F. Rose 1978–1987 (colonel 1987–1990) and M. S. Rosenbaum 1995–2001. Thereafter, a post for a geologist lieutenant colonel became established in the British reserve army, an appointment held by R. I. L. Dow 2006–2011, S. R. S. Matthews 2011–2014, M. H. K. Bulmer 2014– 2019, A. G. Craig 2019–2022, and S. R. S. Matthews again from 2022, each supported by one or two geologist majors. In 200 years, about 21 British military geologists achieved the final rank of major and only 11 the higher rank of lieutenant colonel (the highest rank yet to be attained by a geologist to serve operationally as such in the British Army). Overall, they helped to pioneer and to promote an innovative range of military applications of geology.