Alan William Halliday Pearsall ISO, (born in Leeds on 14 November 1925 - died in London on 31 March 2006) was a naval and railway historian, who served for thirty years from 1955 to 1985 on the staff of the National Maritime Museum, Greenwich.
The eldest son of William Harold Pearsall, (1891–1964), FRS, and professor of freshwater biology at Sheffield University and Manchester University, and his wife Marjorie Williamson, a lecturer in botany, was born at Leeds, while his parents were both lecturers at the University of Leeds. Illness prevented him from attending school between the years of 9 and 13. On completing Grammar School at Morecambe in 1942, he volunteered to join the Royal Navy as a 17-year-old and served in India. After demobilisation and a year of recovery from tropical illness, Pearsall went on to Trinity Hall, Cambridge, where he read history. Completing his degree, he began graduate work in naval history under Professor Gerald S. Graham at King's College London, but did not complete his doctorate.
Encouraged by Graham, Pearsall took a position as a general assistant at the National Maritime Museum in 1955, rising to become Curator of Manuscripts in the 1960s, and then Historian, before he retired in 1985. On his retirement, he was appointed to the Imperial Service Order in recognition of his wide-ranging knowledge of five centuries of British naval history and, as one obituarist characterised it, "his extraordinary value as adviser, teacher and scholarly oracle to colleagues at Greenwich, and to the wider specialist communities and information-seeking public that the museum serves". Although he published no major single work of his own, he published a variety of authoritative articles informed by his deep knowledge of archival materials. Most importantly, his scholarly and informative advice was acknowledged in hundreds of works written by three generations of naval historians.
Pearsall was a member of numerous learned organisations associated with his passionate interests in British naval history, railway history, and fortifications. His most important work, however, was done in connection with the Navy Records Society, which he served as a member of Council and as vice president, as well as editing 80 pages of documents on the nineteenth century in the Society's Centenary volume published in 1993. In addition, he contributed numerous articles to the Oxford Dictionary of National Biography (2004).
Vol. 131 (1993), edited by John B. Hattendorf, R. J. B. Knight, A.W.H. Pearsall, N. A. M. Rodger, and Geoffrey Till.