The company had been formed in 1720.
Established by Royal Charters granted in June 1720 (marine business) and April 1721 (fire and life). It became a subsidiary of the Sun Alliance in 1965.
Its first offices were in the "Rising Sun" in Broad Street, E.C. In August 1720 it moved to a house in Castle Court, Birchin Lane E.C. (formerly the "Ship and Castle" tavern built upon the site of the "Dolphin Tavern" destroyed by the Great Fire in 1666) where it remained until another fire in March 1748. New offices were built at 19 Birchin Lane E.C. and it remained there until 1845. From 1845 to 1922 its head office was at 7 Royal Exchange, E.C. and from 1922-65 at 1 King William Street, E.C.4.
By the 1840s its directors included John Alexander Hankey (who was subsequently deputy governor, then governor) and John Watson Borradaile
See e.g. Blackburn Standard, 25 June 25, 1845
Archives are in London Metropolitan Archives: GB 0074 CLC/B/192-26
History of the Company: G.S. Street, The London Assurance 1720-1920 (London, [Privately printed], 1920). (Copies available in the British Library and the Guildhall Library).