In 1799 he was elected a fellow of the Society of Antiquaries. His first important work, British Monachism (2 volumes, 1802), was a compilation, from manuscripts in the British Museum and Bodleian libraries, of facts relating to English monastic life. The work for which he is best remembered, the Encyclopaedia of Antiquities, appeared in 1824. A sequel to this, Foreign Topography, was published in 1828. Fosbroke published many other volumes, including a detailed examination of the customs observed by English Monks and Nuns "British Monachism."