"Remembering His Royal Highness The Duke of Edinburgh on the first anniversary of his death," read the message alongside the post which was also shared by Prince Charles and Camilla and Prince William and Kate Middleton.
The poem, titled, "The Patriarchs – An Elegy", reads: "The weather in the window this morning is snow, unseasonal singular flakes, a slow winter's final shiver. On such an occasion to presume to eulogise one man is to pipe up for a whole generation - that crew whose survival was always the stuff of minor miracle, who came ashore in orange-crate coracles, fought ingenious wars, finagled triumphs at sea with flaming decoy boats, and side-stepped torpedoes ...
"To study their hands at rest was to picture maps showing hachured valleys and indigo streams, schemes of old campaigns and reconnaissance missions. Last of the great avuncular magicians they kept their best tricks for the grand finale: Disproving Immortality and Disappearing Entirely.
"The major oaks in the wood start tuning up and skies to come will deliver their tributes. But for now, a cold April's closing moments parachute slowly home, so by mid-afternoon snow is recast as seed heads and thistledown."
A funeral for Prince Philip was held last year on April 17 at St George's Chapel in Windsor Castle with just 30 family members and close friends due to Covid-19 restrictions.
A large memorial service held two weeks ago at Westminster Abbey was attended by countless representatives of the many organisations and charities that Philip worked with.
His great-grandchildren, including Prince George, 8, and Princess Charlotte, 6, were also in attendance.
