Less than two weeks after a service of thanksgiving for Prince Philip was held at Westminster Abbey on March 29, the royal family is marking the somber first anniversary of his death.

His Royal Highness Prince Philip died at Windsor Castle on April 9, 2021, and Buckingham Palace said, "It is with deep sadness that Her Majesty the Queen has announced the passing of her beloved husband, His Royal Highness Prince Philip, Duke of Edinburgh. His Royal Highness passed away peacefully this morning at Windsor Castle. The Royal Family joins the rest of the world in mourning the loss of His Royal Highness Prince Philip.

The royal family plans to celebrate today's anniversary of his death in private, HELLO! reports, but Her Majesty the Queen took to social media to post a touching tribute to her late husband, to whom she was married for over 73 years and with whom she had four children: a poem by British poet Simon Armitage, according to PEOPLE magazine, read along with a video montage featuring special moments from Philip's life and the couple's life together. The moments shared included their wedding day and the birth of their four children as well as grandchildren and great-grandchildren.

"In memory of His Royal Highness the Duke of Edinburgh on the first anniversary of his death," the message accompanying the post read. The message was shared by the eldest son, Prince Charles, his wife Camilla, and the Duke and Duchess of Cambridge on their respective social media channels.

The poem, titled "The Patriarchs-An Elegy," reads:

The weather at the window this morning is snow, an unseasonable flake, the last shiver of slow winter. We landed in orange crate corkles, fought an ingenious war, seized victory at sea in a burning decoy boat, and intercepted a torpedo.

As was their husband's duty, they unfolded their plans on billiard tables and car hoods and regrouped at breakfast. What their secret was was anyone's guess and no one's business. Great-grandfathers from birth, they soon became both the inner core and the outer box of the nested doll heirloom.

Like evidence of early man, their shoeprints stand in the hardened soil of rose beds and borders. They were the sons of a constellation out of sync with the solar year, but with their minds set on the great science and heavy questions of the day.

To study their resting hands was to contemplate the canyons, the indigo creeks, the maps showing the plans of old maneuvers and scouting missions. Finally, they saved the best tricks of the great bellicose magicians for the grand finale: the "proof of immortality" and the "total disappearance.

The major oaks of the forest would begin tuning in and the coming sky would pay tribute. But for now, the snow is transforming into seed heads and thistles by midday as the cold late April moments parachute slowly home.

Today, as the poem indicates, is not only the emotional anniversary of the late patriarch of the royal family, but also Charles and Camilla's 17th wedding anniversary.