Corbett v Corbett (otherwise Ashley) [1971] P 83

The High Court declared that a marriage was null and void where both parties were biological males but one (known as April Ashley) had undergone gender reassignment. The judge said that although in many contracts either party could be treated as a man or as a woman, marriage was a relationship between a man and a woman (same-sex marriage was still a long way in the future at this point) and, in the context of marriage, even if not for other purposes, the person was still a biological male.