The Prince of Wales appeared emotional as he heard how the funeral of his father Prince Philip had bestowed "great honour" on the Orthodox Christian world.
An 85-year-old woman told the Prince she had been moved to tears after hearing the Russian Kontakion of the Departed, translated by William John Birkbeck, played at the St George's Chapel service in April 2021.
Dr Jennie Dutchak said: "I thank you personally. His soul rests in peace."
The Prince grasped her arm and sounded moved as he thanked her very much for her words.
The Prince and Duchess both paid a visit to the Ukrainian Community at the Blessed Virgin Ukrainian Orthodox Cathedral in Ottawa, where they heard prayers and thanks specifically to the Royal Family for their support for Ukraine.
The royal couple spoke to a refugee family, a mother and her two sons, who recently joined her sister in Ottawa after being forced to flee their home under Russian shelling.
The Prince and Duchess were also reintroduced to Ukrainian culture and food, with Camilla trying her hand at painting eggs and both attempting to make pierogi.
Dr Dutchak, who spoke to the Prince in the final moments of the visit, said afterwards: "A year ago, at his funeral, his father chose a special hymn.
"Our choir sing it here and it moved me to tears to have a choir sing it at a royal funeral. It was jubilation.
"It is a great honour on every Orthodox Christian that he recognised its sacred beauty. We are all proud."
Prince Philip's funeral, which took place in lockdown, also included the Kyiv Melody, arranged by Sir Walter Parratt.
On the second of a three-day visit to Canada, the Prince and Duchess today joined a church service with members of the Canadian-Ukrainian community, lighting candles and joining prayers.
The Prince at moments appeared lost in thought, closing his eyes as he listened to the melodic service.
The Very Reverend Volodymyr Kouchnir, dean of the St Sophie Ukrainian Orthodox Cathedral in Montreal told them: "Today, your country is truly a friend to Ukraine.
"Having extended a helping hand to our military but also as fellow citizens of our planet. We shall never never never forget that.
"We are sincerely grateful to the Royal Family, to Her Majesty, and to you personally for your help and support for the Ukraine which today is fighting for democratic values and the chance to live as part of the European family.
"God grant you many, many blessed years."
The Prince and Duchess then moved downstairs to the church hall, where they were greeted by a group of five men and women in traditional Ukrainian dress.
They were both introduced to Natalia Stepaniuk, who has been living in Ottawa for ten years after studying at its university, and Olha Rudenko, who left the family's home in Lutsk in March and has since been accepted for a Canadian visa.
Her two sons Stanislav, 16, and Lukian, nine, have travelled with her, while her husband remains in Ukraine to fight.
The Duchess asked her: "Are you coping? It must be so very hard."
After hearing her story, she added: "We are so behind you. We do worry about you so much."
Asking after the children, and hearing that they had started school but the younger was not yet about to speak the language, she reassured them: "Very very soon he'll be speaking English."
The Duchess was then invited to make traditional painted eggs, using a delicate wax technique.
"I've always admired these eggs so much. Are you going to show me?"
Later, the Prince admired her rudimentary lines on an eggshell, as well as the colourful ones painted by the experts with more time.
The couple also tried their hand at making pierogi, the potato and cheese-filled dumpling.
After Camilla made one successfully, it was placed to the side as the group teaching her decided what they should do with the special royal pierogi.
Before they left, the Prince listened to a male voice choir and the Duchess met children from a local Ukrainian school.
After signing the guest book, they took part in a short walkabout with several hundred people outside.
