As Buckingham Palace confirms Camilla was suffering from a form of pneumonia, the Waleses step up to kick off the state visit.

Prince William and his wife Kate will greet Qatar's emir, Sheikh Tamim bin Hamad Al Thani, and his wife on Tuesday as they begin a two-day state visit to Britain. The visit marks the return of Kate to formal welcoming duties after she missed the Japanese emperor and his wife in June while she was undergoing preventative chemotherapy for cancer.

Kate Middleton joined Prince William for rare royal outing amid her cancer recovery, helping Prince William welcome Amir of Qatar and his wife for their state visit to the U.K.