Pope Benedict XVI bid farewell to the College of Cardinals and vowed "unconditional obedience to the new pope" on Thursday, his last day as the leader of the world's more than 1 billion Catholics.

"In these eight years we have faithfully lived beautiful moments of radiant light along the Church's journey along with times when clouds gathered in the skies. We have tried to serve Christ and His Church with a deep and total love, which is the soul of our ministry. We have given the hope that comes to us from Christ and that alone can light the way," the pope told the gathering of cardinals, one of whom will be the future pontiff.

Benedict XVI will step down at 8:00 p.m. on Thursday and will take the title of pope emeritus.

The pope, who turns 86 in two months, announced on Feb. 11 that he planned to step down from the papacy on the last day of this month, becoming the first pope to resign in nearly 600 years.

"Let us remain united in this mystery, dear brothers; in prayer and especially in daily Eucharist, so that we might thus serve the Church and all of humanity. This is our joy, which no one can take from us," the pope told the College of Cardinals.

The Vatican does not plan to hold any ceremony to mark the pope's departure, with the only sign that Benedict is no longer pontiff being the closing of the papal palace's doors by the Swiss Guards.

The papal conclave to elect the successor to Pope Benedict XVI is expected to start in the next few weeks.

Under the Holy See's constitution, the conclave should begin between 15 and 20 days after the papacy becomes vacant to give time for all of the cardinals to arrive in Rome.

The pope will travel on Thursday to the papal summer residence in Castel Gandolfo, some 30 kilometers (18 miles) from Rome, and will stay there until restoration work has been completed on a monastery within the Vatican that will serve as his retirement home, the Vatican Press Office said earlier this month. EFE