They have been the cause of a 10 year legal dispute but now Prince Charles’ ‘black spider’ memos are to be made available for all to read.

On the day of their release, Prince Charles apparently dodged questions on whether he was “worried” about their publication and if he was still writing to ministers, instead saying “very predictable” as he walked past journalists and into a promotional event.

What are Prince Charles’ ‘black spider’ memos?

The letters in question are 27 pieces of correspondence written by Prince Charles to Government ministers between September 2004 and April 2005, and are said to contain “particularly frank” views from the Prince on his opinions and possible interventions on policy.

In pictures: Prince Charles's most controversial moments Show all 10 1 /10 In pictures: Prince Charles's most controversial moments In pictures: Prince Charles's most controversial moments Princely influence The Prince of Wales tried to influence Tony Blair’s government on issues such as grammar schools, alternative medicine and GM food, a BBC radio programme revealed. In pictures: Prince Charles's most controversial moments Charles and grammar schools David Blunkett, right, was among those who disclosed they had been contacted by the Prince of Wales. The former Education Secretary spoke about Prince Charles’ attempts to expand grammar schools, and how he 'didn’t like' it when his suggestion was refused. Rex In pictures: Prince Charles's most controversial moments Ignoring austerity The cost of the monarchy to the taxpayer rose by nearly six per cent last year - more than double the rate of inflation. Travel costs incurred by the Prince of Wales, who has recently begun to take over official duties previously undertaken by his mother, included a £434,000 visit to India with the Duchess of Cornwall, and a charter flight to attend the funeral of Nelson Mandela which cost £246,160 Getty In pictures: Prince Charles's most controversial moments The 'withered' Prince Spain’s King Juan Carlos reportedly said the aging Prince Charles was partly his inspiration for abdicating in favour of Crown Prince Felipe (left). He was reported to have said: 'I do not want my son to wither waiting like Prince Charles' JAVIER SORIANO/AFP/Getty Images In pictures: Prince Charles's most controversial moments Reforming capitalism In May, the Prince of Wales spoke at a major conference about reforming capitalism - despite being advised not to speak on matters of public controversy. Charles' comments over the course of the month had reignited debate about the British monarchy Getty In pictures: Prince Charles's most controversial moments Putin 'acting like Hitler' Prince Charles was claimed to have compared the actions of Russian leader Vladimir Putin to those of Adolf Hitler during a private conversation with a woman who had fled the Nazis PA In pictures: Prince Charles's most controversial moments Australia? Take it or leave it In April the veteran Australian journalist David Marr said the Prince of Wales once privately expressed his belief that if Australia became a republic it would be 'no skin off anyone's nose' Getty In pictures: Prince Charles's most controversial moments Satanic Verses Prince Charles turned his back on Sir Salman Rushdie during his fatwa over publication of The Satanic Verses because he thought the book was offensive to Muslims, it was reported earlier this year. The claims were made by Martin Amis, who said Charles told him that he would not offer support 'if someone insults someone else’s deepest convictions' AP In pictures: Prince Charles's most controversial moments Homeopathy Prince Charles has reportedly pushed for further research on the NHS about homeopathic remedies for a number of years. Labour MPs reacted with fury at the revelation in July 2013 that the heir to the throne had met Health Secretary Jeremy Hunt, with NHS support for homeopathy believed to be on the agenda Getty Images In pictures: Prince Charles's most controversial moments The 'black spider letters' The Guardian has been trying for years to secure the release of a series of 'particularly frank' letters written by Prince Charles to senior Government figures. In October 2012, the attorney-general Dominic Grieve overruled a court's decision to allow access but now, barring a successful appeal to the Supreme Court, Charles's correspondence will be revealed at last

Who were they sent to?

The letters were sent to ministers in seven Whitehall departments during the second term of Tony Blair’s Labour Government. The ministers addressed in the letters were the secretaries of state for business, innovation and skills; environment, food and rural affairs; health; children, schools and families; culture, media and sport; the Northern Ireland Office and the Cabinet Office.

Why are they called the ‘black spider’ memos?

The letters have become dubbed the ‘back spider memos’ due to the Prince’s unique scrawl.

The correspondence reflects Prince Charles’s 'most deeply held personal views and beliefs' Why has there been such a huge legal battle over them?

The previous attorney general Dominic Grieve said the letters reflect the Prince’s “most deeply-held personal views and beliefs”. He claimed the disclosure of the letters could undermine the Prince’s position of “political neutrality” and therefore potentially undermine his ability to perform his duties as monarch, should he become King of England.

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How did this all start?

Guardian journalist Rob Evans made a Freedom of Information request to see the Prince’s letters in 2005. The request was made in an attempt to “find out some solid facts: the contents of actual letters [Prince Charles] had written, and the responses from ministers, so that the public could judge for themselves whether they approved of the letter writing”, Evans wrote in the Guardian.

David Cameron has called the decision to publish the letters 'deeply disappointing' Why are they being published now?

After a 10 year legal battle, the letters are finally being published after the Supreme Court ruled there was “no good reason” for Grieve to have blocked their publication three years ago – a move the former attorney general and minister had used to override the previous decision of an independent tribunal calling for the letters to be published.

Will they be published in full?