A reinvigorated Pope John Paul celebrated his 83rd birthday on Sunday carrying out one of his favorite tasks -- creating new saints as role models for the Roman Catholic Church.
Before some 50,000 faithful packed in St Peter's Square, the white-haired pontiff elevated two fellow Poles and two Italians to sainthood and asked the flag-waving crowd to pray for him.
"No condition and no age are impediments to a perfect life," said the pope, quoting one of the newly proclaimed saints.
"To each and everyone I ask you to continue to pray so that God helps me faithfully complete the mission that he has given me," he said at the end of the 2-1/2 hour outdoor mass, speaking in a clear, loud voice and drawing warm applause.
The end of his long papacy seems less imminent than it did on his last birthday, when he was so weak he could read out only a few lines of his speech before an aide completed the task.
At the time the Vatican was awash with speculation that John Paul might retire, but such talk has faded in recent months as the pope's frail health shows signs of improvement.
Basking in bright summer sunshine, pilgrims on Sunday belted out a spirited "Happy Birthday" for the pope, while the thousands of Poles in the congregation sang their own birthday melody, wishing the pontiff 100 years of life.
One of his closest advisers, Cardinal Joseph Ratzinger, read out a brief birthday greeting in Latin.
Vatican watchers believe the pope may be taking new drugs to tackle the degenerative Parkinson's disease that has ravaged his body and slurred his speech. They say he has also benefited from a rigorous new regime of physical and speech therapy.
But a top churchman said at the weekend that faith lay at the heart of his continued strength.
"If we want to look for the secret weapon that has allowed him to conquer the years and Parkinson's, then we must look to prayer," Cardinal Giovanni Battista Re, head of the Congregation of Bishops, said in an interview with Corriere della Sera daily.
The birthday was another milestone for the pope, who recently became the fourth longest-serving pontiff in history. He will make his 100th foreign trip in June by visiting Croatia and will celebrate his 25th anniversary as pope in October.
Pope John Paul has created almost 470 new saints, more than any of his predecessors. He has also beatified some 1,316 people -- now in sainthood's "waiting room" pending full elevation -- more than all the "blessed" proclaimed by all previous popes since the process of creating saints was reformed in 1588.
The four new saints were Virginia Centurione Bracelli, a 17th century Italian noblewoman who took care of the poor; Maria de Mattias, a 19th century Italian nun who set up schools for the rural poor; Jozef Sebastian Pelczar, a Polish bishop born in 1842 who promoted social work; Urszula Ledochowska, a Polish nun who founded schools and a religious order.
On the eve of his birthday, the pope was awarded an honorary law degree by Rome's La Sapienza University.