The term London's ___ Gallery is referring to the Tate Gallery, which is a network of four art galleries in England. The main gallery is located in London and is known as Tate Britain, while the other three are located in Liverpool, St Ives, and Margate. The Tate Gallery was founded in 1897 and houses a collection of British art from 1500 to the present day. It also has a large collection of international modern and contemporary art.