The Surrey, Kent & Sussex Banking Co. had been established in Southwark, London in 1836 and soon had branches in places like Croydon, Brighton, Maidstone and Woolwich.
It was renamed London & County Bank in 1839. The bank expanded steadily by making a series of acquisitions. By 1875 it had over 150 branches and was the largest bank in Britain.
In 1909 London & County Bank merged with London & Westminster bank to form London County & Westminster Bank.
In 1918 Parrs Bank was acquired and the bank was renamed London County Westminster & Parrs Bank, making it the fifth largest bank in England.
In 1923 the name was simplified to Westminster Bank. The bank continued to expand through acquisition and by 1939 there were 1,100 branches.
In 1968 Westminster Bank merged with National Provincial Bank and the new company, National Westminster Bank Ltd., opened its doors for business on 1st January 1970. NatWest, as it became known, is now part of the Royal Bank of Scotland Group.