Newlyweds Harry and Meghan make first appearance

LONDON, United Kingdom — Newlyweds Prince Harry and Meghan attended their first engagement as a married couple on Tuesday after their spectacular, tradition-defying wedding in Windsor Castle, which was watched around the world.

The two, now officially the Duke and Duchess of Sussex after receiving the title from Queen Elizabeth II, attended a party at Buckingham Palace to celebrate the 70th birthday of Harry's father, Prince Charles.

Tuesday's event is intended as a celebration of Prince Charles's charity work and also includes emergency services personnel who were first responders after the attack in Manchester last year.

At the event, Harry gave a short speech about his father in which he said that the prince's "enthusiasm and energy are truly infectious."

Kensington Palace has said the couple are not intending to go on honeymoon straight away and will instead press ahead with their royal engagements.

Meghan has hinted that she may now champion feminist causes, stating in her official royal family website biography: "I am proud to be a woman and a feminist."

Saturday's wedding blended royal custom with elements of Meghan's African-American cultural heritage and she walked part of the way through the chapel on her own in what was interpreted as a feminist statement.

Harry and Meghan on Monday thanked everyone who took part in their wedding celebrations, as official photographs of the nuptials were released.

"The Duke and Duchess of Sussex would like to thank everyone who took part in the celebrations of their wedding on Saturday," Kensington Palace said in a statement.

"They feel so lucky to have been able to share their day with all those gathered in Windsor and also all those who watched the wedding on television across the UK, Commonwealth, and around the world," it said.

Meghan 'must be careful'

Meghan's biography on the royal family website royal.uk, published on Sunday, focuses on her support for social justice and women's empowerment causes.

The biography mentioned that she campaigned to change the wording on a TV advert that used sexist language when she was just 11 years old and volunteered at a soup kitchen in Los Angeles as a teenager.

There is little mention, however, of her acting career, including her role as savvy para-legal Rachel Zane in the US drama series "Suits."

The description of Meghan as a proud feminist prompted press speculation that she may challenge the royal family's tradition of not getting involved in politically sensitive subjects.

The Daily Mail on Monday sounded a note of caution.

"She must be careful that her enthusiasm for these causes doesn't allow her to be pulled into the political fray. To survive, the monarchy must remain scrupulously neutral," it said.