Kate Middleton joins King Charles for Christmas Day service after 'brutal' year

Kate Middleton ended a "brutal" year by delivering some holiday cheer.

The Princess of Wales was all smiles on Wednesday as she joined her father-in-law, King Charles III, for the traditional Christmas Day walk to St. Mary Magdalene Church.

The service took place at Sandringham, the estate on the windswept North Sea coast that has been a retreat for the royals for generations.

The year has been a tumultuous one for Kate. In January, Kensington Palace announced she had planned abdominal surgery. She was out of sight for several months, sparking conspiracy theories about her health.

While she stepped away from most public duties during her treatment, Kate made two appearances earlier this year. First, during the king's birthday parade in June, known as Trooping the Colour, and during the men's final at Wimbledon in July, where she received a standing ovation.

In September, Kate announced she had completed chemotherapy treatment. In a video announcing her progress, she said the path to full recovery would be long, and she would take it day by day. She said she would undertake some limited engagements through the end of the year.

On Dec. 6, the princess appeared emotional as she hosted her annual "Together at Christmas" carol concert at Westminster Abbey.

"But I think lots of people this year have had such challenging times, and many who are here today," she noted.

In November, William opened up about facing "the hardest year in my life."

The 42-year-old got candid about his "brutal" year during an interview with reporters in Cape Town, South Africa. At the time, he was visiting for the fourth annual Earthshot Prize Awards.

"It's been dreadful. It's probably been the hardest year in my life," said the Prince of Wales, as quoted by People magazine.

"So, trying to get through everything else and keep everything on track has been really difficult," he added.

During his interview, William shared an update on Kate's health, telling reporters she was "doing well."

WATCH: KATE MIDDLETON ANNOUNCES SHE HAS COMPLETED CHEMOTHERAPY TREATMENT

Upon being told he appeared "relaxed," William responded, "I couldn't be less relaxed this year, so it's very interesting you're all seeing that."

"But it's more a case of just crack on, and you've got to keep going," he added. "I enjoy my work, and I enjoy pacing myself and keeping sure that I have got time for my family, too."