Future sons and daughters of Prince William and Kate will now have equal rights to the throne.
At the Commonwealth Heads of Government Meeting all 16 nations - of which the queen is head of state - voted for constitutional changes, bringing equality to the laws of succession.
The Queen - seen here with the Prime ministers of Bangladesh, Australia and the Republic of Trinidad and Tobago - seemed to signify her approval when she made a speech about the theme of the conference, Womens of Agents of Change.
Under the new succession laws the first-born child will automatically become heir to the throne, regardless of gender.
Prime Minister David Cameron stated;
"Put simply, if the Duke and Duchess of Cambridge were to have a little girl, that girl would one day be our queen".
The reforms won't be retrospective so the current line of succession that places the Duke of York and the Earl of Wessex ahead of their older sister the Princess Royal remains unchanged.
Photo: © Rex Features