LONDON - Prince Harry and his new wife Meghan began married life on Sunday after their spectacular, rule-breaking wedding, but will be delaying a honeymoon as they turn immediately to royal duties.

The newly ennobled Duke and Duchess of Sussex staged a huge party after the ceremony on Saturday at Windsor Castle, where they were greeted by around 100,000 people lining the streets and watched by millions around the world.

The beaming couple were seen driving to the evening bash in a vintage Jaguar, Meghan having changed from her sweeping Givenchy wedding gown into a sleek Stella McCartney halterneck dress, with Harry switching his military frockcoat for black tie.

On the bride's finger was a large aquamarine ring, which belonged to Harry's beloved late mother, Diana.

Details of the bash, hosted by Harry's father Prince Charles in a house on the castle grounds for 200 close friends and family, were a top secret although fireworks were seen over Windsor late in the evening.

Some of the celebrities who attended the earlier service, including George Clooney and tennis star Serena Williams, were also spotted heading in.

After staying at Windsor overnight, Harry and Meghan returned to their home at Kensington Palace in London at some point on Sunday afternoon.

They will not be taking a honeymoon immediately, as they are due to attend a charity garden party for Prince Charles, the heir to the throne, at Buckingham Palace on Tuesday.

Meghan and Charles have reportedly forged a strong bond, and he stepped in to escort her to the altar at the wedding after her own father pulled out following a media furor and subsequent heart surgery.

Charles also invited Meghan's mother Doria Ragland, the only member of the Markle family to attend the wedding, for tea before the big day and chatted to her in the church.