Tom Kington, The Guardian, March 1, 2012
"We don't want this material to be secret," said the archivist, waving at an endless row of shelves packed with fading documents that disappeared off into the darkness. "I am really happy people will see what a rich patrimony we have," he added, before wandering further into the bowels of the Vatican's Secret Archive.
Containing more than 50 miles of shelves packed with an unknown number of papal documents spanning 12 centuries, including correspondence with Genghis Khan's grandson, Wolfgang Mozart and Adolf Hitler, the archive is opening up to the public for the first time on Wednesday with an exhibition showing off 100 documents at Rome's Capitoline Museum.
Usually the preserve of select scholars, the archive boasts such treasures as a letter, complete with 81 wax seals, sent by English nobles to Pope Clement VII in 1530 demanding Henry VIII be allowed to divorce Catherine of Aragon, a request the pope turned down, helping prompt the formation of the Church of England.
Lost on the shelves until 1920, the letter will take pride of place in the exhibition alongside an 1887 letter from a North American Indian chief, written on a strip of bark, addressing the pope as the "Grand Master of Prayers", and Galileo Galilei's shaky signature on his retraction in 1633 of his heliocentric views after the Vatican put him on trial for heresy.
From 1493 there is the papal bull that hurriedly split the new world between Spain and Portugal after Columbus's return from the Americas, neatly managed by drawing a line from pole to pole 100 leagues west of the Azores. Long bestowed with an aura of mystery, notably in the film of Dan Brown's Angels and Demons, which depicted the archive as a high-tech steel bunker of secrets, the archive is in real life a more down-to-earth maze of grey corridors with bare cement ceilings, winding staircases and sleepy scholars consulting an index system dating from the 18th century.
"The 'secret' in Secret Archive comes from the Latin for private or personal, since this is the pope's private archive," said archivist Enrico Flaiani.
Secret or not, the archive gives an amazing snapshot of history. Since Vatican employees put their first document – a Vatican guide to writing formal letters – on the shelf in the 8th century, the collection has coped with some odd tomes, including a 60kg , 37cm-thick wooden-bound book documenting the history of a Roman noble family, and a 1650 letter written on silk and folded inside a stick of bamboo in which the Ming empress Wang tells the pope she has converted to Christianity and changed her name to Helena.
The archive is full of letters in secret code sent to Rome by papal nuncios as far back as the 14th century, experience of which allowed Vatican spies to crack the coded messages sent between the Savoy royal family and Italian politician Camillo Cavour in the 19th century.
Not all the archive's secrets are on show. Ducking down a narrow gap between grey metal shelves, Flaiani comes up against a section locked off behind a wire fence containing correspondence after 1939 that researchers suspect may hold clues to the Vatican's real relationship with the Nazis. Turning, he points to a set of empty shelves. "When the documents are made available they will go there," he said.
The exhibition is not the first time documents have left the archive. Napoleon took the documents with him when he went back to Paris from Italy in 1810, with around a quarter of the documents never making it back to Rome, especially records of Inquisition trials, many of which were shredded and sold to a cardboard factory. Some documents which did make it back still bear their French reference number.
From a maze of underground corridors, Flaiani rounds off his tour by darting up a winding staircase leading to the Tower of Winds, used by astronomers who invented leap years in 1582 to create the modern Gregorian calendar, named after the then serving pope Gregory XIII.
The archivist's final flourish is back down the stairs in a reading room, where he dons white gloves and unveils prized documents that will not be among the 100 exhibits across the Tiber at the town hall. Among them is a 1579 letter to the pope from Elizabeth I, signed with a flourish of zigzags, asking the Vatican to free a prisoner. "Just to show there is still a lot of stuff to be seen here," he said.
Apart from the letter from English nobles asking the pope if Henry VIII can divorce, other highlights of the Lux in Arcana exhibition include:
• The abdication deed of Queen Christina of Sweden, the controversial monarch rumoured to be a hermaphrodite, who gave up her throne in 1654 to convert to Catholicism, move to Rome and entertain artists.
• The 1521 decree excommunicating the German monk Martin Luther which helped launch the Reformation.
• A short, sad note written by the jailed Marie Antoinette to her brother in law in 1792 or 1793, shortly before she was executed.
• A 1550 letter from Michelangelo moaning about hold-ups in his work on the dome of St Peter's basilica.
• Documents from 1308 about the trials of the Knights Templar, who were disbanded by Pope Clement V.
• A letter from Mary Queen of Scots, written in 1586, a few weeks before her execution for allegedly plotting to assassinate Elizabeth I, in which she declares her allegiance to the "universal" Catholic church.
• This article was amended on 29 February 2012. The original referred to a letter sent by British to Pope Clement VII in 1530 demanding Henry VII be allowed to divorce Catherine of Aragon. This has been corrected. The article was also amended to clarify the following sentence: Napoleon shipped the whole collection back to Paris in 1810.