The Princess of Wales is recovering in hospital following planned abdominal surgery, Kensington Palace confirmed on Wednesday.
Kate, 41, likely to spend between two and three months recuperating and is not expected to return to public duties until after Easter based on current medical advice, the Palace said.
The royal mum-of-three was last seen publicly on Christmas Day when she and her husband, Prince William, and their three children, Prince George, Princess Charlotte and Prince Louis attended church with the royal family.
Kate looked beautiful in a bespoke royal blue Alexander McQueen coat over a navy roll neck jumper and a matching hat by Juliette Millinery.
She accessorised with the late Princess Diana’s sapphire and diamond earrings and a suede Emmy London clutch bag.
As the royals made their way to St Mary Magdalene church on the Sandringham estate, Kate held her daughter Princess Charlotte’s hand.
Cameras also picked up a sweet moment between the Princess and her youngest son, Prince Louis, as they departed from the service.
The Waleses were seen chatting with locals in the crowd who had gathered to catch a glimpse of the royals on Christmas Day, with Kate accepting bouquets of flowers.
Earlier in December, extended members of the royal family also stepped out to attend Kate’s Christmas carol concert at Westminster Abbey.
Kate’s third carol service was in honour of all those who work to support babies, young children and families in communities across the UK and a celebration of the golden opportunity that the birth of a new baby brings.
Kensington Palace also released footage of George, Charlotte and Louis helping their mother Kate out at a baby bank charity in Holyport near Maidenhead last month.
Kate – a future Queen – is expected to remain in hospital at the London Clinic for ten to 14 days.
The nature of the Princess’s condition has not been revealed although Kensington Palace confirmed it was not cancerous.
Prince William has postponed a number of engagements to be by his wife’s side and to care for their three children.
Kate marked her birthday just over a week ago, with the monarchy’s official social media accounts sharing a new behind-the-scenes photo of the princess at the King’s coronation.
The Princess usually enjoys good health but was previously admitted to hospital while pregnant after suffering from hyperemesis gravidarum – severe morning sickness.
Buckingham Palace announced just an hour and a half after Kensington Palace’s shock news that Charles, 75, will be treated in hospital next week for an enlarged prostate.
The Palace said Charles’s condition was benign and he would be having a corrective procedure.