A giant birthday banner is seen in the background as Pope Benedict XVI is driven through the crowd at the end of his birthday Mass at the Vatican, 15 Apr 2007

Pope Benedict XVI celebrated his 80th birthday a day early with a Mass in his honor Sunday in a sunny St. Peter's Square. Tens of thousands of faithful followers joined the pope in prayers of thanks to God for his long life. Sabina Castelfranco reports from Rome.

Cardinals, priests and tens of thousands of faithful followers joined Pope Benedict for a special birthday Mass in Saint Peter's Square. Pope Benedict, who was born April 16 1927, in Marktl Am Inn, a riverside town in the Bavaria region of Germany, celebrates his 80th birthday on Monday.

Among the crowd in the square were also some of Pope Benedict's fellow countrymen and women in traditional Bavarian dress. The first to address the crowd and the pope at the start of the ceremony was the dean of the College of Cardinals, Angelo Sodano.

Cardinal Sodano said the pope's 80th birthday is reason for spiritual happiness for all. He urged the pope to continue in his guidance with love.

In his homily, the pope said the faithful had gathered to reflect on what he called his "not brief" life.

The pope thanked God for all his gifts. The pope said he experienced the significance of the family. He thanked God for his brother and sister who, with their help, were close to him during the course of his life.

Pope Benedict also recalled his calling to the priestly ministry and his election as pope.

Referring to his election in 2005, the Pope said God had brought him new help to deal with the growing weight of responsibility.

Pope Benedict said that knowing that many pray for him gives him joy, and he expressed gratitude to those who put up with his shortcomings. He then thanked God and all of the faithful and pledged to carry out his mission with increasing dedication.