The North British & Mercantile Insurance Company (N. B. & M.) was established in Edinburgh in 1809 to do business as a fire insurance company, originally with the name the North British Insurance Company.
The first major fire in the company’s history broke out in a Glasgow warehouse in 1810 during celebrations for the birthday of King George III. The cost of the fire damage was far greater than it should have been because the firemen were too drunk to put out the blaze.
In 1823 the firm extended its business to include life insurance. The firm continued to grow and obtained a Royal Charter in 1824. In the 1860s the company opened businesses and agencies across the world, including the Far East and Africa.
In 1862 the North British Insurance Company merged with the Mercantile Fire Insurance Company, subsequently changing its name to the North Britsh & Mercantile Insurance Company.
In 1890 N. B. & M. entered into an arrangement with the Civil Service Insurance Society whereby society members would be insured by the company at special rates. This link continued until 1996. From 1901 business was extended to include all classes of marine risks and later to general insurance. By 1911 the company was transacting fire, life, marine, accident, fine art, burglary and motor insurance. N. B. & M. was incorporated as a limited company in 1920.
In 1959 it became a subsidiary of the Commercial Union Assurance Company Ltd. The company maintained head offices in Edinburgh until 1963 and London until 1969. Since June 2006 it has been registered as a non-trading company.