Pope John Paul II is marking his 84th birthday with a cake baked by his cook, Sister Germana, and the publication of a new autobiography.
The book is expected to sell millions of copies worldwide
The 200-page book, Get Up and Let Us Go , follows his journey from new Bishop of Krakow to being elected as Pope.
It contains intimate reflections on the pontiff's faith and details his experiences in Communist-era Poland.
Despite deteriorating health the Pope maintains a gruelling schedule of appearances and foreign trips.
Vatican officials said the Pope's best birthday present would be a visit to the Swiss capital Bern at the beginning of June, when he will meet thousands of young Roman Catholics.
John Paul II is renowned for his record-breaking number of trips abroad, but it will be the first time he has gone outside of Italy since he visited Slovakia in September.
During that trip the Pope appeared weak and was unable to deliver his speeches himself, sparking speculation that he was nearing death.
However, just a month later he was able to take part in silver jubilee celebrations to mark his 25th year as head of the Roman Catholic Church and since then has much recovered.
Although confined to a wheelchair and suffering from the symptoms of Parkinson's Disease, he appeared well on Sunday as he canonised six new saints at a service in St Peter's Square attended by thousands.
The Pope's new book, which will be translated into several languages, is a sequel to Gift and Mystery, an account of his early years in the priesthood, which was released in 1996.
Reluctance to lead
In it the Pope recalls how he was on a canoeing trip down the River Lyna in Poland when he was elected Bishop of Krakow in 1958.
He was immediately called to Warsaw by Cardinal Stefan Wyszynski, and travelled in a truck laden with sacks of flour to reach the city, reading a copy of Ernest Hemingway's The Old man and the Sea en route.
When the cardinal informed him of Pope Pius XII's decision he says he exclaimed: "Your eminence, I am too young - I am only 38."
The Pope spurned a promising theatre career to become a priest
To which Cardinal Wyszynski replied: "This is a weakness of which we are quickly cured. Please do not oppose the Holy Father's wish."
Afterwards the sport loving priest returned to his canoeing trip, with a warning to make sure he was back in time for his consecration.
Despite his meteoric rise through the ranks to become the first non-Italian pope in more than 450 years, the Pope, or Karol Wojtyla as he was then still known, claims his first love was the theatre.
In his youth the Pope was both an actor and a playwright, and in the book he describes how it was the example of Polish saint Albert Chmielowski (1845-1916), a popular artist who became a priest, that persuaded him to do the same.
During the 20 years that the autobiography covers, the Pope says he clashed frequently with Poland's Communist authorities, who sought to suppress the Church.
He organised secret meetings and engaged in what he calls a "constant fierce struggle" to get a church built in one of Krakow's new socialist-designed suburbs, Nowa Huta.
The Pope's health has greatly improved in recent months
John Paul II says that when he later became Pope he tried to use his globetrotting not only to spread the Catholic gospel, but also as a way to ensure that the struggling Catholics of Poland were not forgotten.
He says he strategically chose to make his first official visit to Mexico, a similarly secular state, in the hopes that it would open up a path to Poland.
"I thought the communists in Poland would not be able to refuse me a visit to my homeland if I were received by a nation with a secular constitution, such as Mexico had," he writes.
The Pope is enormously popular, especially in Central and Eastern Europe, as he is the first ever Slavic pope.
But liberal Catholics accuse him of being too authoritarian and archaic in his views.
In his new book the Pope ponders whether in fact he has been strict enough in his leadership, saying that part of his role is to admonish his flock when they stray.
"I think that in this aspect, maybe I have done too little. There is always this problem of how to balance authority and service. Perhaps I need to criticise myself for not having tried hard enough to lead," he writes.