A glamorous new portrait ofKing Charles IIIandQueen Camillais in the mail.

During the King’smeeting with President Volodymyr Zelenskyy of Ukraineat Buckingham Palace earlier this month, apreviously unseen pictureof King Charles, 74, and Queen Camilla, 75, was displayed on a table behind them. The image appeared to be a formal portrait of the couple taken duringthe first state banquetof the monarch’s reign in November 2022, when Cyril Ramaphosa, president of South Africa, made his three-day state visit to the United Kingdom.

Now, the portrait is being used for a special reason: to celebrate the 100th birthdays of U.K. residents!

Twitter user SpikeArmstrong alsoshared photosof his grandfather’s birthday card on social media, sharing a look at the message inside.

“My wife and I are so pleased to know that you are celebrating your one hundredth birthday on 21st February, 2023,” the message from the King said. “This brings our warmest congratulations and heartfelt good wishes on such a special occasion.”

King Charles and Queen Camilla.Chris Jackson/Getty

King Charles III and Camilla, Queen Consort during the State Banquet at Buckingham Palace on November 22, 2022 in London, England. This is the first state visit hosted by the UK with King Charles III as monarch, and the first state visit here by a South African leader since 2010.

King Charles and Queen Camillasent out their first round of birthday cardsfrom the palace shortly after Charles became monarch following the death ofQueen Elizabethin September.

However, those cards featured a photo of the royal couple from the summer of 2018.

Thousands of birthday cards are sent from Buckingham Palace each year to residents celebrating their 100th and 105th birthdays…and every year thereafter. Couples celebrating their 60th, 65th and 70th wedding anniversaries receive a card as well.

The tradition dates back to 1917 during the reign of King George V. DuringQueen Elizabeth’s reign, approximately 1.3 million cards were sent to mark birthdays and anniversaries across the U.K., the realms and the overseas territories, per Buckingham Palace.

Can’t get enough ofPEOPLE’s Royals coverage?Sign up for our free Royals newsletterto get the latest updates on Kate Middleton, Meghan Markle and more!

King Charles and Queen Camilla.Andrew Milligan - Pool/Getty

King Charles III and Camilla, Queen Consort, waves as they leave Dunfermline Abbey, after a visit to mark its 950th anniversary, and after attending a meeting at the City Chambers in Dunfermline where the King formally marked the conferral of city status on the former town on October 3, 2022 in Dunfermline, Scotland.

To receive a card, residents mustapply onlinewith a copy of the celebrant’s birth certificate or passport. Only current citizens of the U.K., countries where King Charles is head of state or U.K. overseas territories are eligible to receive messages.

source: people.com