text: A top-secret security operation was launched to protect Prince Charles from a feared terror attack by Welsh nationalists at his investiture ceremony, newly released official papers reveal. The eyes of the nation were on the heir to the throne for the historic event on July 1, 1969, but behind the scenes, Prime Minister Harold Wilson was convinced terrorists campaigning for Welsh independence would target Charles – then 20 – at the Caernarfon Castle ceremony. Classified documents obtained by The Mail on Sunday under Freedom of Information laws show that the Government sent Metropolitan Police officers to Wales in the lead-up to the ceremony to join the fight against extremists who had already set off a series of bombs. Threat: The Queen invests the Prince at Caernarfon Castle in 1969 after secret police were sent to Wales in fear of an attack on the monarchy . The targets of the operation were members of the nationalist groups Movement for the Defence of Wales (MAC) and the Free Wales Army (FWA). The files show Wilson’s government approved plans to send officers from the Met to Wales to run a secret unit that would spy on the extremists. The files do not include any details about the methods employed by the officers, but there are several references to ‘intelligence gathering’ and the ‘dissemination of information’. On August 8, 1968, the Home Office wrote to all Chief Constables in Wales informing them of the new police unit that would be headed by two senior Met officers. The letter stated: ‘The Home Secretary thinks it necessary to adopt exceptional means of keeping himself informed about the criminal activities of extremists in Wales and the action being taken to deal with them.’ It added: ‘Officers from Scotland Yard will have the particular assistance of an intelligence unit which will be created from (and detached from) the regional crime squad.’ Wilson later voiced his fears in a letter to James Callaghan, his then Home Secretary, on February 4, 1969. He wrote: ‘The security position, as I understand it, still gives cause for concern; and we must be as sure as we can that all possible precautions are taken. 'I want to feel confident that, if necessary, I can advise The Queen that in the Government’s opinion the whole programme between now and July can go forward without significant risk of any untoward interruption.’ In previously classified documents Wilson told his then Home Secretary he wanted to be able to tell the Queen the programme would be able to proceed . He added: ‘I should be grateful, therefore, if you would let me have a note describing the current and prospective security situation regards Wales, together with the arrangements which are in train for protecting the Prince of Wales.’ In April that year, Wilson also considered cancelling plans for the Prince, who was then a Cambridge undergraduate, to spend a term at the University of Aberystwyth prior to the ceremony after being alarmed by the fact extremists had exploded a bomb at Cardiff police HQ that month. He asked Callaghan: ‘Would the Home Secretary please reconsider in the light of the latest outrage in the police headquarters in Cardiff. Might we be wiser to cancel Aberystwyth?’ But the increased surveillance did not stop the groups’ activities. On the evening before the investiture, two members of MAC, Alwyn Jones and George Taylor, were killed when a bomb they had been placing near government offices exploded prematurely. John Jenkins, the MAC leader who was later sentenced to ten years in jail for his role in the movement, last night insisted he had never intended to harm the Prince of Wales. He said: ‘We did what we did because we wanted to change the nature of the investiture. We didn’t want it to be an occasion for dancing around the maypole and I think we achieved that.’ Buckingham Palace, the Home Office and the Met Police declined to comment. The targets of the operation were members of the nationalist groups Movement for the Defence of Wales (MAC) and the Free Wales Army (FWA) (pictured above)
target: Wilson voiced fears in a letter to then Home Secretary James Callaghan .
  He said he wanted to be able to tell the Queen 'programme' could proceed .
  Metropolitan police were sent to Wales to join the fight against extremists .