Pilgrims from around the world flocked to St Peter's Square in the Vatican to see Pope Benedict XVI give his last Sunday blessing before he steps down.
From his window overlooking the cheering crowds he used his last Angelus to tell them he was following God's wishes by resigning, reports the BBC.
He said: "The Lord is calling me to climb the mountain - prayer is not an isolation from the world,"
"I am not abandoning the Church and shall continue to serve it in a manner more adapted to my age and strength."
According to the Telegraph, his voice was cracked with emotion as he addressed the crowd.
After stepping down he will live in a monastery within Vatican City, devoting his time to prayer and meditation.
He is the first Pope to resign in over 600 years blaming deteriorating health.
It was reported this week that Pope Benedict XVI’s decision to resign was influenced by the discovery of a gay “network” in the Vatican that led to some clergymen being blackmailed by outsiders.