17th-century English radicals

Why were the security services so obsessed with the Marxist historian Christopher Hill?

What did the great Marxist historian Christopher Hill think of orgies? Michael Braddick’s splendid and judicious biography doesn’t ponder this question. However, it strikes me as worth posing since, for a three-week period in the winter of 1978, an ensemble of actors (including the future Hollywood star Bob Hoskins) could be found naked at the National Theatre simulating group sex in Hill’s name. The actors were performing in Keith Dewhurst’s radical stage adaptation of Hill’s masterpiece of 17th-century popular history The World Turned Upside Down (1972) and were embodying what it might have been like to be enthusiastic members of one of the radical millenarian sects at the centre of