The marriage of Prince William to Catherine Middleton is on of the most significant royal events of recent times. As second in line to the throne, the elder son of the much-mourned Diana, Princess of Wales-whose famous sapphire-and-diamond engagement ring he bestowed on his future bride-William embodies the hopes and expectations of millions of people around the world. And as a 'commoner' who will become a princess, Catherine brings romance and freshness to a very traditional union.