Prince William and his wife, the Duchess of Cambridge, are expecting their third child, Kensington Palace confirmed on Monday. The child will become the fifth in line to the British throne and, if the child is a boy, will be the first in the immediate royal family to be affected by changes to the line in succession. The Succession to the Crown Act in 2013 ended the system of male preference primogeniture— where princes take precedence over their older sister—which had been in place since the 1701 Act of Settlement.