Earl Spencer

Earl Spencer

The brother of Britain's Princess Diana has warned the monarchy could be lost in 100 years.

Earl Charles Spencer - who famously gave an inflammatory eulogy at his late sister's funeral in 1997 - believes the current generation of royalty is safe thanks to the popularity of his nephew, second-in-line to the throne Prince William, but doesn't know how safe the royal family are in the long term.

Speaking an America - and notably not mentioning Diana's ex-husband, and current heir, Prince Charles - he said: "Maybe in 100 years things will change. "William's popular, so the throne is secure for the next generation."

Charles was speaking as he promoted his historical book 'Killers Of The King: The Men Who Dared To Execute Charles I' and claimed the fate of the monarch in the tome is a warning about what could happen in the near future.

He said: "Charles I's murder brought a reduced monarchy plus the idea you could actually stand against the king.

"His penniless son, who couldn't even pay his hotel bill, went into exile. We went 10 years without a king."

And the earl claimed Brad Pitt is keen to turn the tale into a Hollywood blockbuster.

According to the Daily Mail newspaper, he said: "Lionsgate and Brad Pitt's company are interested in filming the story."