Prince William became "quiet, withdrawn, and not himself" during his brief 2007 split from Kate Middleton , with palace staff telling RadarOnline.com the future king's behavior at the time was unusually "closed off" and "disturbing to witness."

The then 25-year-old royal had ended his long-term relationship with Middleton, now the Princess of Wales, after years of mounting public pressure and scrutiny from the press.

The pair had met while studying at the University of St. Andrews in Scotland in 2001 and had been together for much of their twenties. Article continues below advertisement

Withdrawn and Distant Prince Tap Here To Add Radar Online as A Trusted Source

But insiders say the separation – which lasted only a few months – deeply affected William, revealing a rare glim

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