Prince Harry honored Princess Diana by having flowers laid at her grave on Mother's Day

• Prince Harry arranged for flowers to be laid at Diana's grave on Mother's Day in the UK.
• Meanwhile, Prince William's children wrote cards to their "Granny Diana."

Prince Harry honored his mother, the late Princess Diana, from California as the UK celebrated Mother's Day on Sunday.

"The Duke arranged for flowers to be laid at his mother's grave on Sunday morning," a spokesperson for the Duke of Sussex told Insider.

The duke currently resides in Santa Barbara, and therefore would have arranged for someone else to deliver the flowers to Diana's grave at the Spencer family estate in Althorp, Northamptonshire in England.

The spokesperson did not confirm who laid the flowers on the duke's behalf.

Diana played a major part in Harry and Meghan Markle's sit-down interview with Oprah, which aired on CBS on March 7.

The Duchess of Sussex paid tribute to Diana by wearing her Cartier tennis bracelet during the interview.

Harry compared his and Markle's experience in the royal family to his mother's during the interview, as he said his "biggest concern was history repeating itself."

"For me, I'm just really relieved and happy to be sitting here talking to you with my wife by my side because I can't begin to imagine what it must have been like for her [Diana] going through this process by herself all those years ago," he said.

Meanwhile, Prince William's children paid tribute to their grandmother by writing Mother's Day cards to the royal, Insider's Joshua Zitser reported.

-The Duke and Duchess of Cambridge (@KensingtonRoyal) March 14, 2021

Prince George (7), Princess Charlotte (5), and Prince Louis (2) never met Diana, but they still write cards every year to remember their "Granny Diana," Kensington Palace wrote on Twitter.