From the NatWest Group website:
“This joint stock bank was established at 8 Moorgate, City of London, in 1839 as Union Bank of London with a paid-up capital of £211,500.

In 1841 it acquired the business and premises of Metropolitan Bank (est. 1839), bankers of London. Branches were opened in Argyle Place (1839), Pall Mall (1840), Charing Cross (1841), Temple Bar (1855), Chancery Lane (c.1868),

Holborn Circus (1870),…

The place was described in Charles Dickens‘ Dictionary of London (1879) as “perhaps… the finest piece of street architecture in the City”.” (Wikipedia)
…Bayswater (1882), Fenchurch Street (1886), Tottenham Court Road (1886), Sloane Street (1888) and Southwark (1892). The head office was moved to Princes Street, City of London, in 1844.
It acquired Dixon, Brooks & Dixon in 1859; Chasemore, Robinson & Sons in 1891 and London, Commercial & Cripplegate Bank in 1900. The company was severely undermined by a £250,000 fraud in 1860. The bank assumed limited liability in 1882 as Union Bank of London Ltd. In 1887 a new head office building was erected in Princes Street. By 1902 there were 24 branches in London and its suburbs.
In 1902 the bank amalgamated with Smith, Payne & Smiths and its country connections: Samuel Smith & Co of Nottingham; Smith, Ellison & Co of Lincoln; Samuel Smith, Brothers & Co of Hull; Samuel Smith & Co of Derby; and Samuel Smith & Co of Newark. The new bank was called Union of London & Smiths Bank Ltd. In 1903 its paid-up capital was £3.55m, its balance sheet totalled over £41m and it had 51 branches. In 1903 it acquired Wigan, Mercer, Tasker & Co of Maidstone; London & Yorkshire Bank; and Prescott’s Bank of London.
In 1918 the bank amalgamated with National Provincial Bank of England

to form National Provincial & Union Bank of England.
Branches: In 1917 231 branches were operating.”
Architectural details
Holborn branch:



Chancery Lane branch

https://www.jdwetherspoon.com/pub-histories/england/london/the-knights-templar-near-fleet-street

From the website Exploring London:
“The pub, which opened in 1999, was formerly the home of the Union Bank of London Ltd, built in 1865 to the design of architect FW Porter.
https://www.dia.ie/architects/view/4384/PORTER-FREDERICKWILLIAM
Original features inside the Grade II-listed building – built in the ‘high Renaissance’-style – include cast iron columns and ornate detailing.”
