The Nullity of Marriage Act 1971 was the first time in British law that marriage was defined as being between a male and a female. A marriage could therefore be annulled if the partners were not respectively male and female.

The Act was repealed, and the provisions re-iterated by the Matrimonial Causes Act 1973, which is still in force.

See also

• Same-sex marriage in the United Kingdom
  Same-sex marriage in the United Kingdom
  Same-sex marriage is not currently legal in the United Kingdom. Marriage laws vary in the countries of the UK, however they all currently prohibit marriages between same-sex couples. Since 2005, same-sex couples are allowed to enter into civil partnerships, a separate union which provides the legal...
  
  
• Marriage in the United Kingdom
  Marriage in the United Kingdom
  Marriage in England and Wales is between a man and a woman. Civil partnerships became available to same-sex couples in December 2005 and grant rights and responsibilities identical to civil marriage...