London: The Princess of Wales, Kate Middleton penned an emotional letter to the Irish Guards, and shared her apologies for missing from a major rehearsal for Trooping the Colour, King Charles' birthday parade, maintaining a low profile amidst her cancer diagnosis.

Kate expressed deep regret at missing the ceremony, which was the penultimate rehearsal for the Trooping the Colour march.

The letter read, “I wanted to write and let you know how proud I am of the entire regiment ahead of the Colonel’s Review and Trooping the Colour. I appreciate everyone trooping this year has been practising for months and dedicating many hours to ensuring their uniforms and drill are immaculate.”

She further stressed that it is a “great honour” to be a Colonel, adding that “I am very sorry that I’m unable to take the salute at this year’s Colonel’s Review.”

“Please pass my apologies to the whole regiment, however, I do hope that I am able to represent you all once again very soon.”

The Irish Guards shared a letter from the Princess of Wales, 42, in a post on X (formerly Twitter) on Saturday and wrote, “The Irish Guards were deeply touched to receive a letter from our Colonel, Her Royal Highness, The Princess of Wales this morning. We continue to wish Her Royal Highness well in her recovery and send Her our very best wishes.”

Kate’s letter is a major hint she will miss the ceremony, a major fixture in the royal calendar, although reports suggest the princess could watch from the Buckingham Palace balcony.

The Colonel's Review comes before the official birthday celebrations of the King on Saturday, June 15, which typically involve the customary appearance on the Buckingham Palace balcony. The Colonel's Review mirrors The King's Birthday Parade, with the only difference being the inclusion of extra mounted officers in the latter.

Princess Kate has chosen to keep a minimal public presence following her announcement on March 22 regarding her cancer diagnosis and ongoing chemotherapy treatment. She had appealed for time, space, and privacy for her family when she made the announcement.