It was a year of intense student unrest throughout the world. In Paris, strikers joined students to man barricades in the streets in May. A huge, violent demonstration against the Vietnam War took place outside the US embassy in Grosvenor Square, London, in October.
The Prime Minister's security files for 1968, some of which are released today, reveal tip-offs from members of the public of disruption by students of events attended by the Prime Minister. In June, Mr Wilson received a confidential letter from a senior member of staff at an English language school in London, warning him of a plan, organised by the German student leader "Danny the Red" Cohn-Bendit, to "wreck" an appearance by the Prime Minister at a university award ceremony. The letter revealed: "Two French students attending this school - both from the Sorbonne university and of good family and prospects - inform me that you are to preside at some ceremony at Bradford University sometime next month. It would appear that the gangster `Danny the Red' has given instructions that the ceremony should be wrecked."
The letter was handed over to Special Branch and, amid special security precautions, Mr Wilson presented an honorary degree at Bradford to M Roche, reader at the Sorbonne.
Shortly before, Tony Benn found himself confronting the Campaign for Nuclear Disarmament (CND) during 1968, ready to oppose it "with whatever force was necessary" to stop protesters penetrating Britain's nuclear weapons factory. But Mr Wilson doubted that he was up to the job. Mr Benn - who has supported the campaign for most of the years since then - was the Minister of Technology in a Labour Cabinet at the time. His department oversaw the development of nuclear energy for war and peace.
Between these two events, the Cabinet gave urgent consideration to what might happen during CND's traditional Good Friday march from London to the Royal Ordnance Factory at Burghfield, Berkshire, and the nearby Atomic Weapons Research Establishment (AWRE) at Aldermaston.
Mr Benn told the Cabinet preparations had been made to resist any protest invasion at Burghfield, where Polaris nuclear missile warheads were manufactured. His permanent secretary had already sent a note to 10 Downing Street, saying all the conventional explosives and fissile (radioactive) materials used to make the weapons were being moved into the maximum-security magazines and bunkers in the factory's fortified core.
Any protesters who managed to penetrate the perimeter and outer defences would be blasted by firemen's hoses and have police dogs set on them.
But the Prime Minister was unconvinced, and urgent talks were held between ministers on the day before the 12 Aprilmarch, both within Cabinet and outside it. With three forces involved - the AWRE's, the Ministry of Defence's force and the civilian, Thames Valley force - he complained to Cabinet that the ultimate responsibility for controlling any attempted invasion by protesters was unclear. He ordered his Home Secretary, James Callaghan, to meet Mr Benn and the Defence Secretary, Denis Healey. He insisted military helicoptors should be put on stand-by to ferry in extra police and even troops if needed.
Mr Callaghan warned the Cabinet that extreme left-wing foreign students, especially West Germans, were likely to infiltrate the march, intent on provoking confrontation.
He blamed them for the "new and more violent tactics", seen at the Grosvenor Square demonstration. In the end, the march was more heavily policed than ever before and there was little disorder.