Harry was photographed leaving Windsor Castle after reportedly paying a private visit to the chapel, which is on castle grounds.
Harry, who now lives in California with his wife Meghan and their two children, traveled to London this week to attend an awards ceremony sponsored by WellChild -- a charity for terminally ill children, of which he is patron -- but he is not expected to meet with his father King Charles III or his brother, Prince William during the trip.
Harry, who stopped in the U.K. on his way to Germany for the Invictus Games, spoke about the queen in his WellChild speech Thursday, saying, "I was unable to attend the awards last year as my grandmother passed away ... I know, exactly one year on, that she is looking down on all of us tonight, happy we're together, continuing to spotlight such an incredible community."
While Harry was in Windsor, Charles, the eldest of the queen and the late Prince Philip's four children, and his wife Queen Camilla attended a special church service Friday near Balmoral Castle, where the queen died Sept. 8, 2022, at age 96.
During the queen's 70-year reign, she spent summers at Balmoral Castle, the royal family's longtime retreat in Scotland, a tradition that Charles is now continuing.
Charles also released a statement to the public, noting that he is remembering his mother's "long life, devoted service and all she meant to so many of us."
"In marking the first anniversary of Her late Majesty's death and my Accession, we recall with great affection her long life, devoted service and all she meant to so many of us," Charles said in his statement. "I am deeply grateful, too, for the love and support that has been shown to my wife and myself during this year as we do our utmost to be of service to you all."
A new photo of the queen was also released Friday to mark the anniversary of her death.
The photo, which had not been previously released to the public, was taken at Buckingham Palace on Oct. 16, 1968, by photographer Cecil Beaton. It was chosen specifically by Charles, according to the palace.
Charles' eldest son William and his wife, Kate, the Prince and Princess of Wales, remembered the queen Friday while visiting Wales. The couple attended a private service at St. Davids Cathedral and shared a series of photos of the queen on social media.
"Today we remember the extraordinary life and legacy of Her Late Majesty Queen Elizabeth. We all miss you. W & C," the couple captioned the photos.
Last September, Elizabeth's death kicked off a period of official mourning for the royal family that lasted until seven days after the queen's state funeral, which took place Sept. 19, 2022, at Westminster Abbey.
Over the past year, the royal family has undergone change both privately and publicly as they have adapted to life without the queen, who led her family and her country for seven decades.
The most public transformation came last May, with the coronation of Charles and Camilla, the first coronation held in the U.K. since Elizabeth's in 1953.
Other family members have also taken on new roles since the queen's death, most notably William and Kate, who became the Prince and Princess of Wales.
In the book, Harry detailed his fractured relationships with Charles and William, as well as his thoughts on the future of the monarchy. Neither Buckingham Palace nor members of the royal family have commented publicly on the allegations Harry made in "Spare."
In addition to internal family turmoil, Charles and the royal family have also faced growing unrest against the monarchy over the past year, in the wake of Elizabeth's death.
During Charles' coronation in May, hundreds of anti-monarchy protesters gathered in Trafalgar Square in Central London, where they booed loudly and chanted "not my king." The issues that motivated the protesters, such as the monarchy being out of date and linked to colonialism, have continued to present serious challenges to Charles as he tries to keep the crown relevant.
On the first anniversary of the queen's death Friday, one anti-monarchy group, No More Royals, held a small rally outside of Buckingham Palace.