Kate Middleton and Prince William shared a smile during Commonwealth Day services at Westminster Abbey on Monday, March 10.

King Charles III and Catherine, Princess of Wales have attended the annual Commonwealth Day service, a year after both were forced to cancel because they were receiving cancer treatment. The event at Westminster Abbey on Monday celebrated the Commonwealth's "powerful influence for good in the world".

Their Majesties The King and The Queen attended the annual Commonwealth Day Service at Westminster Abbey on Monday.

The Commonwealth service began around 3 p.m. U.K. time, and upon their arrival at Westminster Abbey, the royals were greeted by members of the Shree Muktajeevan Swamibapa Pipe Band (SMSPB) from Shree Swaminarayan Mandir in Kingsbury—the world’s first Hindu eco-temple.

The Princess of Wales returned to the Family of Nations when she joined the King and Queen in celebrating Commonwealth Day. Kate missed the Westminster Abbey service last year, as did Charles, with both receiving treatment for cancer during a troubling health scare period for the monarchy.

Britain's King Charles arrived for the annual Commonwealth Day service at London's Westminster Abbey on Monday (March 10) for annual celebrations for the international organization he leads. Greenland: Why is it valuable?

Catherine, Princess of Wales, joined Britain’s King Charles III and other members of the royal family in celebrating Commonwealth Day on Monday, attending an event at London’s Westminster Abbey filled with performances from countries across the association.

King Charles and Princess Kate make an appearance at the annual Commonwealth Day Service in the United Kingdom. We'll be bringing you the very latest updates, pictures and video on this breaking news story.