Kate Middleton baffles eagle-eyed fans with mysterious change on royal duty return

The Princess of Wales took on her biggest royal role since the end of her cancer treatment by taking part in the Qatar state visit to the UK - and eagle-eyed royal fans were left pondering a mystery when it came to her striking outfit

The Princess of Wales delighted royal fans with her return to royal duty in her most significant appearance since finishing chemotherapy treatment.

Kate, 42, joined Prince William as well as King Charles as they officially welcomed the Emir of Qatar to the UK for a two-day state visit. The princess took part in greeting the Emir and his wife at their London residence before escorting them to a ceremonial welcome at Horse Guards Parade.

Paying tribute to the guests, Kate wore a maroon coat by Sarah Burton for Alexander McQueen and a hat by Sahar Millinery in a matching colour as well as knee-high burgundy boots by Gianvito Rossi. Maroon and white are known to be the national colours of Qatar.

After the ceremonial welcome at Horse Guards Parade, Kate along with King Charles, William and their guests, took part in a carriage ride back to Buckingham Palace, where a lunch was being held before a viewing of a small exhibition of items associated with their Qatar's relationship with the UK.

But when Kate reappeared for this part of the visit, eagle-eyed fans noticed a change in the princess. That's because she appeared to have ditched her coat and instead was wearing a coat dress in a very similar colour by Eponine London. Her boots had also been slipped off in favour of a pair of heels. And after noticing the tweak to her outfit, royal fans wondered if Kate had worn the Eponine coat dress under her Alexander McQueen one - or if she got changed completely when back at the palace.

One fan took to Instagram and pondered: "This coat [McQueen one] has a very unusual lapel arrangement. I'm wondering if she had the coat dress seen in the palace exhibition room later underneath but it looks too fitted to have another dress underneath. Guess we won't know."

Kate's appearance yesterday comes amid a busy week and as she will be hosting her annual Christmas carol service at Westminster Abbey on Friday when she is expected to be joined by her children and husband for the event. Kensington Palace said Kate wanted the theme of this year's carol service to celebrate those supporting others in need, with a focus on the importance of love and empathy.

It said: "The service will shine a light on individuals from all over the UK who have shown love, kindness and empathy towards others in their communities." The Palace added: "This year, Her Royal Highness wanted to celebrate the many people supporting those in need – individuals who have inspired, counselled, comforted, and above all else shown that love is the greatest gift we can receive.

"This theme takes inspiration from the Christmas story which encourages us to consider the experiences of others and the important human need of giving and receiving empathy." It will be the fourth time Kate has staged her Together At Christmas carol service, which is supported by The Royal Foundation. The event will be filmed as part of a special programme on ITV1 and ITVX on Christmas Eve.