The book, one of only two originals preserved, will be displayed as part of an exhibition dubbed "The Church of the Slovenian Language", marking the 450th anniversary of the release of the book.

"Cerkovna ordninga", considered to be the first legal text written in Slovenian, describes Trubar's vision of the organisation of the Protestant Church in Slovenia, the rites, as well as Lutheran teachings and the activities of the Church in general.

It is considered to be one of the most important works by Trubar also because it establishes Slovenian as a language of church rites.

"Cerkovna ordninga" was released in Germany's Tübingen in 300-400 copies, of which most were confiscated or destroyed soon after the publication. The only undamaged copy from Dresden was lost during World War Two.

In 1971, a copy with damaged edges of final pages was discovered in the Vatican library, while the copy to be exhibited now is perfectly preserved and was discovered by chance in the City Archives of the German town of Memmingen only last October.

According to NUK director Martina Roznam Salobir, the exhibition, which will be open until 4 October, will present the circumstances in which "Cerkovna ordninga" was written, its contents and its influence on other Protestant writers as well as on the development of Slovenian culture.

Špela Spanžel of the Culture Ministry said Turbar's works were more than cultural heritage of Slovenians, "they are a symbol of our presence in the European culture from the 16th century onwards".

Several other important Trubar's works will be on display as part of the exhibition along with books and documents connected to the release of "Cerkovna ordninga". Among them there will be also an order on confiscation of the book and eviction of Trubar issued by Archduke Karel (the son of Ferdinand I) dated 15 December 1564.