The North British Insurance company was established on 19 October 1809. The company obtained a royal charter in 1824, and in 1862, the company merged with the Mercantile Fire Insurance Company and became North British & Mercantile Insurance Company. The company was incorporated as a limited company on 1 November 1920 and became a subsidiary of the Commercial Union Assurance Company Ltd in 1959.

The Yorkshire Insurance Company was established in 1824 as the Yorkshire Fire and Life Insurance Company. On 27 May 1908, the company changed its name to the Yorkshire Insurance Company and was registered as a limited company on 3 June 1908. The company purchased its first fire engine in November 1824 tackled fires in York until the city corporation assumed responsibility for all fire fighting in 1876. The company was acquired by the General Accident Fire and Life Assurance Corporation Ltd in 1968.

Established in 1861 as the London and Lancashire Fire Insurance Company. In 1919 it acquired the Law Union and Rock Insurance Company Limited. In 1920 its name was changed to the London and Lancashire Insurance Company Limited. In 1961 it was acquired by, the Royal Insurance Company Limited.