©National Archives

Fleet Clandestine Marriage Register, 1716-20. Entry for the Marriage of Alexander Selkirk to Sophia Bruce. Until 1754, couples could legally marry without a formal church ceremony. Those who wished to marry in secret, for whatever reason, could do so on condition that the ceremony was presided over by a clergyman.

One of the most notorious centres for 'clandestine' - or secret - marriages was the area around Fleet Prison in Farringdon Street, London. Here the venues ranged from taverns and coffee-houses to churches and workshops. One such marriage involved Alexander Selkirk, a Scottish sailor who was marooned between 1704 and 1709 in the Juan Fernandez Islands in the South Pacific. His story provided the idea for Daniel Defoe's Robinson Crusoe, first published in April 1719. The entry for Selkirk's marriage is shown here, in one of many 'Fleet' registers held by the PRO. These registers report at least 250,000 marriages between 1690 and 1754 when such marriages were outlawed.