Mary Adelaide Wilhelmina was the daughter of Adolphus, Duke of Cambridge, the seventh son of George III. In 1866 she married Prince Francis Paul Louis Alexander, Duke of Teck (1837-1900), eldest son of Prince Alexander of Württemburg. She was the mother of May of Teck, who became the wife of George V.

She was known as the Princess of Cambridge until her marriage, after which she was known as either the Princess or Duchess of Teck. Enormously popular with the British public, she was also affectionately known as 'Fat Mary'.