Prince Harry and Meghan, the Duchess of Sussex, posted a tribute Friday to Prince Philip following news of his death.
The couple updated their website Archewell to read: “In loving memory of His Royal Highness, the Duke of Edinburgh."
"Thank you for your service… you will be greatly missed," the message continued.
Prince Harry is one of Prince Philip's eight grandchildren.
Prince Philip, 99, Queen Elizabeth II's husband, died Friday morning, weeks after he had been admitted to a London hospital for a medical procedure and treatment for an infection.
A statement posted on the royal family's website said that he "passed away peacefully this morning at Windsor Castle."
"Further announcements will made in due course. The Royal Family join with people around the world in mourning his loss," the statement read.
In a February appearance on "The Late Late Show with James Corden," the Duke of Sussex said he kept in touch with his grandparents via the Zoom video chat platform. Prince Harry and his wife, along with their 1-year-old son Archie, moved to Los Angeles after the couple announced their plans to "step back" from their royal duties at Buckingham Palace.
"They've seen Archie running around," he said.
"My grandfather, instead of pressing leave meeting, he just goes 'doof,'" Prince Harry said gesturing how his grandfather closes the laptop. "I'm like, 'OK, bye.' "