FILE Britain's Prince William, background centre, Kate, the Duchess of Cambridge, background and Prince Harry take part in a relay race, during a training event to promote the charity Heads Together, in London, Sunday, Feb. 5, 2017. The world watched as Prince William grew from a towheaded schoolboy to a dashing air-sea rescue pilot to a father of three. But as he turns 40 on Tuesday, June 21, 2022, William is making the biggest change yet: assuming an increasingly central role in the royal family as he prepares for his eventual accession to the throne.(AP Photo/Alastair Grant, Pool, File)