Share Tweet Pin Email By Katherine Tinsley 10:07pm PDT, Sep 5, 2025 _ Prince William was just 15 when his mother, Princess Diana, died at 36 in 1997. The loss "made" the future king, he said while reflecting on her death years later, in one of just a handful of times he's publicly opened up about her in the nearly three decades since she died.Keep reading to see what he had to say on the subject...MORE: Follow Wonderwall on MSN for more top news _ In the 2017 documentary Diana, Our Mother, Prince William reflected on losing Princess Diana at a young age. "It'll either make or break you.