In 1937 the Duke of Windsor married the divorcee Wallis Simpson. What was her surname at birth?

Wallis, Duchess of Windsor (born Bessie Wallis Warfield; 19 June 1896 – 24 April 1986), commonly known by her second married name of Wallis Simpson and previously as Wallis Spencer, was an American socialite whose intended marriage to the British king Edward VIII caused a constitutional crisis that led to Edward's abdication.

In 1931, during her second marriage, to Ernest Simpson, she met Edward, then Prince of Wales. Five years later, after Edward's accession as King of the United Kingdom, Wallis divorced her second husband to marry Edward.

The King's desire to marry a woman who had two living ex-husbands threatened to cause a constitutional crisis in the United Kingdom and the Dominions, and ultimately led to his abdication in December 1936 to marry "the woman I love". After abdicating, the former king was created Duke of Windsor by his brother and successor, King George VI. Edward married Wallis six months later, after which she was formally known as the Duchess of Windsor, without the style "Her Royal Highness". She was instead styled as "Her Grace", a style normally reserved for non-royal dukes and duchesses.

Wallis and Edward married on 3 June 1937 at the Château de Candé, loaned to them by French millionaire Charles Bedaux. The date would have been King George V's 72nd birthday.