'People were living different 68s at the same time'

50 years ago, riot police entered the Sorbonne University in Paris to bring a student sit-in to an end. Soon barricades were going up and violent clashes were breaking out in the Latin Quarter. But rebellion in May 1968 wasn't just a French phenomenon. It extended far and wide: from the LSE in London, to the streets of Prague, and on to the civil rights movement in the US. We spoke to Richard Vinen from King's College London about his new book "The Long 68': Radical Protest and its Enemies".