Davies attended Rugby School, and thereafter read mathematics and modern languages at King's College, Cambridge.
After being made Assistant Keeper in 1932 he called for improved research on the paintings in the collection, which would eventually come to fruition in the series of catalogues inaugurated by Davies and still being produced by the Gallery today.
His scholarly work was interrupted from 1938 to 1941 by the need to find a safe home for the National Gallery's paintings at the onset of the Second World War, away from the aerial bombardment of London.
After the artworks were safely transferred to Manod Quarry near Ffestiniog, North Wales, Davies was able to make his research in total seclusion.
Davies's stated aim as director was to make the National Gallery the main public purchaser of artistic masterpieces, in which he succeeded, acquiring notable works by Caravaggio (Salome with the Head of Saint John the Baptist), Tiepolo (An Allegory with Venus and Time [1]) and Henri Rousseau (Tiger in a Tropical Storm [2]).