The Vatican Library will be given back a letter written by Christopher Columbus in 1493 announcing his discovery of the New World after it was stolen and replaced with a forgery.

The Columbus Letter is an account of the explorer's first experiences in the New World and was addressed to King Ferdinand and Queen Isabella of Spain, who funded the expedition.

'I discovered many islands inhabited by numerous people,' he wrote.

'I took possession of all of them for our most fortunate King by making public proclamation and unfurling his standard, no one making any resistance.

'All these island are very beautiful, and of quite different shapes; easy to be traversed, and full of the greatest variety of trees reaching to the stars.'

The letter was translated into Latin and copies were distributed around Europe, including one sent to the Vatican in 1921. But later it emerged the copy held by the Vatican was a fake and the original had been stolen. It was one of several other copies across Europe that had stolen and replaced with expert forgeries.

Robert Parsons from Atlanta bought the letter from a rare book dealer in 2004, unaware that had been taken from the Vatican.

His widow, Mary Parsons, agreed to relinquish her rights to it and give the letter back to the Vatican. It was presented to the chief Vatican archivist, Archbishop Jean-Louis Brugues, and the prefect of the library, Bishop Cesare Pasini, by Callista Gingrich, ambassador to the Holy See, in a special service on Thursday.