 Since her death, Springfield has been widely commended as the leading British soul singer of the twentieth century.Springfield was born Mary Isabel Catherine Bernadette O'Brien on 16 April 1939 in West Hampstead, the second child of Gerard Anthony "OB" O'Brien (1904–1979) and Catherine Anne "Kay" O'Brien ("née" Ryle; 1900–1974), both of Irish descent.Springfield's elder brother, Dionysius P. A. O'Brien (born 2 July 1934), was later known as Tom Springfield.