Documents from the trial of Galileo Galilei in the 17th century are displayed in an exhibition of Vatican archives that opened at Musei Capitolini in Rome in 2012. Photo: IC

The Vatican Secret Archives, containing millions of documents spanning 12 centuries, are no longer "secret."

Pope Francis has renamed the priceless archives, which include letters about King Henry VIII's requests to divorce Catherine of Aragon and marry Anne Boleyn that led to the English Church's 1534 split with the Catholic Church in Rome.

They also hold the original acts of the 1633 trial of astronomer Galileo by the Roman Inquisition which condemned him for heresy for teaching that Earth revolves around the sun.

The Vatican said the new name will be the Vatican Apostolic Archives. This removes any potentially "negative nuances" from the Latin word "secretum" which the pope said in a decree was closer to "reserved" than "secret" when the archives were first named around 1610.

The collection of papers and parchments that date back to the 700s make the archives one of the world's most important research centers.