 The third director , Sir Frederick William Burton , laid the foundations of the collection of 18th @-@ century art and made several outstanding purchases from English private collections . The acquisition in 1885 of two paintings from Blenheim Palace , Raphael 's <unk> Madonna and Van Dyck 's Equestrian Portrait of Charles I , with a record @-@ setting grant of £ 87 @,@ 500 from the Treasury , brought the Gallery 's " golden age of collecting " to an end , as its annual purchase grant was suspended for several years thereafter . When the Gallery purchased Holbein 's Ambassadors from the Earl of Radnor in 1890 , it did so with the aid of private individuals for the first time in its history . In 1897 the formation of the National Gallery of British Art , known unofficially from early in its history as the Tate Gallery , allowed some British works to be moved off @-@ site , following the precedent set by the Vernon collection and the Turner Bequest . Works by artists born after 1790 were moved to the new gallery on Millbank , which allowed Hogarth , Turner and Constable to remain in Trafalgar Square . 
