The Union Bank of London was established at 8 Moorgate Street, London in 1839. The bank assumed limited liability in 1882 and five years later a new head office was erected in Princes Street. By 1902 the bank had 24 branches in London and its suburbs.
In 1902 Union Bank of London Ltd. merged with Smith, Payne & Smiths. The new bank was called Union of London & Smiths Bank Ltd. The bank expanded steadily and in 1917 there were 231 branches in operation.
In 1918 Union of London & Smiths Bank Ltd. amalgamated with National Provincial Bank of England Ltd. to form National Provincial & Union Bank of England Ltd. The new bank continued to grow until its merger with Westminster Bank in 1968 and is now part of the Royal Bank of Scotland.