This is the second notable Irish Guards event Middleton will miss due to her busy or her illness.

In a letter shared by the Irish Guards on Saturday, Kate Middleton expressed apologies for her inability to attend an annual pre-Trooping the Colour event, but said that she hoped to join them again in the near future. The letter follows news that Princess Kate, the honorary Colonel of the Army regiment, would not attend today’s Colonel’s Review as she recovers from cancer treatments.

This is the second notable Irish Guards event Middleton will miss due to her illness, following her absence at its St. Patrick’s Day Parade in March. Prior to the 2024 event, she’d attended even before she was named to her honorary role, starting in 2012. (She missed only one St. Pat’s parade, in 2016).

Kate Middleton has eschewed public events since her January surgery, which was later revealed to be related to a diagnosis of an unspecified cancer. News reports earlier this year had suggested that she would make her return to public duties in time for events surrounding June 15’s Trooping of the Colour, an military annual parade held in honor of the current monarch’s birthday.

But last month, it was announced that former military commander Lieutenant General Sir James Bucknall would step in for her role in this weekend’s practice ceremony.

(Yes, King Charles III’s birthday isn’t until November, but as noted for his first Trooping the Colour in 2023, the event is held in spring to take advantage of the preferable weather.)

In a letter shared by the Irish Guards on social media, Middleton wrote, “I wanted to write and let you know how proud I am of the entire Regiment ahead of the Colonel’s review and Trooping of the Colour.

I appreciate everyone trooping this year has been practicing for months and dedicating many hours to ensuring their uniforms and drill are immaculate

While Middleton’s letter apologizes only for missing Saturday’s review, it’s unlikely that she’ll attend next weekend’s main event. Sources who spoke with Vanity Fair confirmed that King Charles will attend, riding in a State Landau carriage, while Middleton’s husband, Prince William, is also expected to participate.