Prince William has made a rare public appreciation of his grandmother Queen Elizabeth II as she is about to celebrate her becoming the longest serving monarch in the history of Great Britain.

In the preface of a new biography, Elizabeth II: The Steadfast, the Prince said this.

As the Queen, 89, approaches Sept. 9, the day when she will break Queen Victoria's record reign, William highlighted her "example and continuity," that is "rare among leaders."

Praising her "kindness and sense of humor" and love for her family and her home, Prince William wrote she has been a "model for a life of service."

"From a personal point of view, I am privileged to witness the private side of the Queen, as a grandmother and a great-grandmother," he wrote. "The Queen's kindness and sense of humor, her innate sense of calm and perspective, and her love of family and home are all attributes I experience first-hand."

Source: XINHUA