Benedict Cumberbatch has said it was "an extraordinary bit of serendipity" that he was told he was related to Richard III - while he was dressed as the king.
The actor plays the monarch in the last two parts of The Hollow Crown, BBC Two's adaptations of Shakespeare's history plays.
The king's skeleton was discovered in 2012 and last year, while he was in character as the monarch, Benedict was told that they were cousins.
He told the Radio Times: "I was literally dressed as Shakespeare's version of Richard III when I received an email from Leicester University saying that I was a not-altogether-ridiculously-distant descendant of Richard.
"I'm a third cousin 16 times removed, which is still distant, but puts me ahead of an awful lot of other people."
The star, 39, was asked to read a poem by the Poet Laureate Carol Ann Duffy at the reinterment in Leicester Cathedral.
"To have been present when Richard III found his resting place was moving," he said. "I was at the burial of a king."
Benedict will be seen as the monarch - who was killed at Bosworth Field in 1485, at the end of the Wars of the Roses - in Henry VI, Part II and in Richard III.
He said the series strikes unsettling chords even in our time.
"These films stretch way beyond the remit of historical or period drama," he said.
"They are about everything we're facing - all the debates about who we should ally ourselves with, whether we should be part of Europe, and how deep these divides go within a society.
"And the violence of medieval warfare has a resonance with what's going on with extremism in the world...
"To see the headlines, and then read the day's shooting script, realising we are enacting a beheading, literally taking someone's head off their shoulders - sad to say, these are things which are still part of our world."
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