Duchess of Cambridge

Duchess of Cambridge is the principal courtesy title held by the wife of the duke of Cambridge. Two women have been known as duchesses of Cambridge: Princess Augusta of Hesse-Kassel, from her marriage to Prince Adolphus in 1818 until her death in 1889, and Catherine Middleton, since her marriage to Prince William in 2011.
Prince George, Duke of Cambridge, son of Prince Adolphus and Princess Augusta, married Sarah Fairbrother in contravention of the Royal Marriages Act 1772. Since the marriage was legally void, she could not share his titles.