Queen Mary of Denmark shared some sad news on 12 April, taking to social media to announce the death of her father. Translated to English, a message shared on King Frederik and Queen Mary’s Instagram account read: “It is with great sorrow that Her Majesty, The Queen, announces that her father, Professor John Dalgleish Donaldson, has died in Hobart, Tasmania. He was 84 years.”

Captioning a black and white photo of Professor Donaldson, which was captured by King Frederik’s wife on 23 March 2026, was a statement from Mary: “My heart is heavy, and my thoughts are grey. My beloved father has passed away. But I know that when the grief settles, the memories will brighten my day, and what will remain strongest is love and gratitude for everything he gave me and taught me.”

The post also revealed that Professor John Donaldson’s health has been declining over the past few years and that the Queen last visited her father at the end of March, where they shared precious time together.

John Donaldson was a Professor of Applied Mathematics, born in Scotland on 5 September, 1941. The family will hold a private memorial service at a later date.

Queen Mary’s childhood

Mary's father, John Donaldson, walked her down the aisle to marry Crown Prince Frederik in 2004© Getty Images
Mary’s father, John Donaldson, walked her down the aisle to marry Crown Prince Frederik in 2004

Queen Mary is the youngest of four children of her parents, Henrietta (née Horne), who was an executive assistant to the vice-chancellor of the University of Tasmania, and who passed away in 1997, and her father, John Dalgleish Donaldson.

The royal has two older sisters, Jane Stephens and Patricia Bailey, and an older brother, John Stuart Donaldson. While Mary was primarily educated in Australia, she began her school years at Clear Lake City Elementary School in Houston, Texas, while her father was working at the Johnson Space Center.

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Mary’s return home

The news of Professor Donaldson’s passing comes after Queen Mary returned to her native Australia for a royal tour with her husband in March 2026. The couple had a jam-packed schedule while Down Under, including a reception at Government House in Hobart on 19 March and a walkabout at Hobart Waterfront, as well as ‘An Evening in the Garden’ at the Royal Botanic Gardens in Melbourne the day before.

The Danish royals were attending a reception at Government House in Hobart, Tasmania © Getty Images
Queen Mary of Denmark and King Frederik X of Denmark attend a reception at Government House

In an emotional speech, Mary described the trip as a “unique, rewarding, moving, exciting, [and] curious” experience.

Denmark's King Frederik X and Queen Mary arrive ahead of 'An Evening in the Garden' at the Royal Botanic Gardens in Melbourne on March 18© POOL/AFP via Getty Images
Denmark’s King Frederik and Queen Mary arrive ahead of ‘An Evening in the Garden’ at the Royal Botanic Gardens in Melbourne

Meanwhile, her husband added: “For me, Australia has held a special place in my heart ever since I walked into that bar and got lost in a conversation that has never ended,” recalling the night he first met Mary.

Queen Mary and King Frederik© AFP via Getty Images
Frederik and Mary met in Australia in 2000, during the Summer Olympics in Sydney

“Mary, you had the courage to leave your beloved home and build a new life with me as far away as possible. For that, I will always be grateful.”