Princess Diana never forgave Sarah Ferguson for one betrayal that ended their friendship: book

Princess Diana and Sarah Ferguson were once inseparable, famously dubbing themselves the "Terrible Twins" and the "Wicked Wives of Windsor." But a devastating rift between the royal rebels ended their friendship for good.

The claim comes from royal author Andrew Lownie, whose expanded edition of "Entitled" delves deeper into the lives and controversies surrounding the former Duke and Duchess of York.

Fox News Digital reached out to Ferguson's spokesperson for comment. A spokesperson...