Following their exchange of vows, the couple's main titles became the Duke and Duchess of Cambridge.

BBC: Royal wedding: Thousands in Northern Ireland celebrate

But TV audiences did not witness an exchange of vows until 21 years later, when Prince Charles married Lady Diana Spencer.

BBC: Royal weddings: A brief history

It wasn't, strictly speaking, a wedding but it certainly looked and felt like one, with a highly traditional liturgy complete with choirs, familiar hymns, and an exchange of rings and vows.

ECONOMIST: The Anglican Communion

That has led the administration to reject the idea of offering North Korea additional aid in exchange for new North Korean vows to abide by agreements it has repeatedly abrogated.

WSJ: U.S. Fortifies Hawaii to Meet Threat From Korea