London, Oct 5 : The mysteries surrounding the Order of the Knights Templar could soon be exposed after the Vatican announced the release of a key document which has not been seen for almost 700 years.

The Vatican is planning publication of ‘Processus contra Templarios’, a book on the suppression of the Knights Templar, based on material from the Vatican Secret Archives.

The Knights Templar, a religious order established in Jerusalem in 1118, rose to prominence during the Crusades, and became a formidable military and political force in Europe in the 12th and 13th century.

But when Jerusalem fell to Muslim rule in 1244, rumours circulated that the knights were heretics who worshipped idols in a secret initiation ceremony.

In 1307, King Philip IV of France ordered the arrest and torture of all Templars, following which Pope Clement V forcibly suppressed the order. Ever since, the Templars have been thought of as heretics.

But rumors about the secrets of the military order have been disseminated for centuries. The Knights Templar’s secrecy has given birth to endless legends, including one that they guard the Holy Grail.

The order has also figured in a number of recent fictional works including The Da Vinci Code and Indiana Jones and the Last Crusade.

The Vatican office of the Secret Archives will unveil the book, containing "a previously unpublished and exclusive edition of the complete acts of the original hearing against the Knights Templar," on Oct 25.

The new book is based on a scrap of parchment discovered in the Vatican's secret archives in 2001 by Professor Barbara Frale.

"This is proof that the Templars were not heretics. The Pope was obliged to ask pardon from the knights. For 700 years we have believed that the Templars died as cursed men, and this absolves them,” the Telegraph quoted Prof Frale, as saying.

‘Processus contra Templarios’ will be a special collector's edition, with only 799 copies produced. (ANI)