Pope Benedict's new book on Jesus Christ will hit the shops after Easter but it's already an international best-seller, one of its publishers said on Thursday.
The book, which is called Jesus of Nazareth, is the first Benedict has written since becoming pope 21 months ago.
Don Claudio Rossini, head of the Libreria Editrice Vaticano which is publishing it jointly with Italy's Rizzoli group, said the book will come out in more than 20 languages, including Russian, Japanese and Korean.
By the end of February more than 20 contracts had already been signed with publishers abroad, including Random House which will publish the book in English, Rossini said
The figure of Christ presented by Benedict in the book was "the result of more than 50 years of research, study and personal meditation," he said.
Announcing its publication last November, the publishers said Benedict stresses in the preface of the work that it is "absolutely not" a work of Catholic doctrine and so his papal infallibility does not come into play.
"It is just the expression of my personal research...and so everyone is free to contradict me," he writes.
The German pope also says in the preface that he has decided to publish what he has written so far because he does not know "how much time and how much strength" he has to complete the work.
He tells readers that he has been working on it in "all spare moments" since his election. He started it in the summer of 2003.
It is a historical and theological presentation of the figure at the centre of Christianity, which draws on hundreds of works of modern research into the figure of Jesus Christ.
The pope explains in the introduction that he is increasingly concerned that the idea of Jesus's identity is becoming confused, both for people inside and outside the Church.
Some people just see him as a "revolutionary" or as a "mild moralist," and there is a widespread view that little is known about Jesus that is certain, he says.
"This sort of situation is dramatic for the faith because it casts uncertainty on its central reference point," he continues, adding: "I believe that Jesus is a historically convincing figure".
Vatican spokesman Father Federico Lombardi noted that if the pope had spent all his spare time on the book it clearly contained a message he saw as "very significant".
"With his book the pope intends to carry out a service to sustain the faith," he said.
Benedict's predecessor, John Paul II, was also a prolific writer, both before and after becoming pope. His biggest success was his 1994 book, Crossing the Threshold of Hope, which was immediately an international best-seller and has been translated into 39 languages.
