The Queen's only daughter, Princess Anne, married Mark Phillips, a lieutenant in the army, at Westminster Abbey. An estimated 500 million television viewers around the world were believed to have watched the ceremony. Princess Anne wore an embroidered Tudor-style wedding dress with a high collar and medieval sleeves. Lieutenant Phillips was in the full scarlet and blue uniform of his regiment, the Queen's Dragoon Guards. The wedding was a national holiday. Thousands lined the streets of central London to watch the occasion. The couple met through their mutual interest in horse riding, and had got engaged in May 1973. At the time it was only the second occasion in over 200 years that a member of the British royal family had married a commoner. The previous commoner to marry into the royal family was the Queen Mother in 1923. Princess Anne and Mark Phillips had two children: Peter, born in 1977, and Zara in 1981. The couple were divorced in April 1992.