Tens of thousands of pilgrims greeted Pope Benedict XVI with cheers as he was driven through St. Peter's Square in the Popemobile one final time. The 85-year-old pontiff waved at the throngs of clergy and lay people from around the globe who had travelled to Rome to bid him farewell.

Following readings from the Gospels in several languages, the pope spoke to the crowd more candidly than usual about his eight years at the head of the Roman Catholic Church.

"What I heard in my heart [when I was elected] was, 'God, why are you asking me to do this and what are you asking me to do? You are giving me a heavy burden," said Benedict.

"Eight years later, I'd like to say that God guided me, has been close to me, I have his presence everyday. We have had moments of joy…and difficult moments," he added.

Benedict reiterated his resignation stemmed from the desire to do what was best for the worldwide congregation. Given his diminishing strength, he could no longer lead.

'Choppy waters' part of the job

The German pontiff's time leading the world's 1.2 billion Roman Catholics has been characterized by heightened tensions within the Church. Revelations of abuse scandals, and most recently, the leaking of Vatican documents by one of Benedict's butlers in the so-called "Vatileaks" case, threw the pope into one public relations problem after another.

While held in high esteem by many conservative Roman Catholics, the widely-respected theologian had difficulty winning the affection of others who preferred a more extroverted spiritual leader, like his predecessor Pope John Paul II.

Nevertheless, Benedict XVI expressed warm thanks toward the many who were keeping the Church alive.

"Right now my soul is open to embrace the entire Church and I'd like to thank everybody for the help I have received and the charity that's inside the Church," he said, adding that he never felt alone in such a public position.

Vatican officials said an estimated 50,000 tickets had been distributed prior to the event. Tens of thousands more filled the remaining open spaces. The crowds began gathering hours before the event, waving flags from around the world and banners in different languages thanking the pope for his service.

Penultimate day

The final public audience came one day before Pope Benedict retires to a private life of prayer and meditation.

On Thursday, Benedict is scheduled to fly from Rome to the papal summer residence of Castel Gandolfo. The public will be able to catch one final glimpse of him before the official end of his papacy at 8 p.m. local time, at which point the Swiss Guard will also leave the residence.

The College of Cardinals is scheduled to meet early next week to discuss the current priorities for the Church and to set the date for the conclave, where the next pope will be elected.

As Benedict is only the second pope to resign of his own free will since the Middle Ages, popes generally hold the office for the remainder of their lives once elected, his decision has raised many questions about what role he will assume and how his life will look in the future.

He will receive two new titles - "Roman pontiff emeritus" and "emeritus pope" - but will continue to be addressed directly as "Your Holiness."

kms/rg (AFP, AP, dpa)