Henry honoured his pledge of December 1483 to marry Elizabeth of York. They were third cousins, as both were great-great-grandchildren of John of Gaunt. The marriage took place on 18 January 1486 at Westminster. The marriage unified the warring houses and gave his children a strong claim to the throne. The unification of the houses of York and Lancaster by this marriage is symbolised by the heraldic emblem of the Tudor rose, a combination of the white rose of York and the red rose of Lancaster.