Queen Camilla's extended illness explained as royal cancels major appearance

On Tuesday, Her Majesty, who reduced her duties for the Qatar state visit this week as she recovers, told guests at the Buckingham Palace festivities her recent illness developed into a form of pneumonia, according to People.

The Queen, who did not attend the traditional kickoff at Horse Guards Parade in London Tuesday morning, was driven to the palace in the afternoon for the luncheon welcoming Sheikh Tamim bin Hamad Al Thani, the amir of Qatar, and his wife, Her Highness Sheikha Jawaher bint Hamad bin Suhaim Al Thani, the outlet reported. 

A representative for Buckingham Palace did not immediately respond to Fox News Digital's request for comment. 

On Nov. 5, Her Majesty was advised to take a "short period of rest," effectively canceling Camilla's events for that week. 

"Her Majesty The Queen is currently unwell with a chest infection, for which her doctors have advised a short period of rest," a statement from the palace said, according to the BBC.

The royal family has been dealing with multiple health scares. Buckingham Palace announced King Charles III had been diagnosed with cancer in February, while Middleton announced her own cancer diagnosis one month later. 

Kate Middleton had undergone planned abdominal surgery, and it was determined her condition was "non-cancerous." However, further testing showed "cancer had been present." She was advised to begin chemotherapy by her medical team.

"This, of course, came as a huge shock, and William and I have been doing everything we can to process and manage this privately for the sake of our young family," the Princess of Wales said in a prerecorded message in March. "As you can imagine, this has taken time. It has taken me time to recover from major surgery in order to start my treatment. But, most importantly, it has taken us time to explain everything to George, Charlotte and Louis in a way that is appropriate for them, and to reassure them that I am going to be OK."

Fox News Digital's Lauryn Overhultz contributed to this post.