Vatican City - Tens of thousands of the faithful attended the funeral Mass for the late pope emeritus Benedict XVI in St Peter's Square in the Vatican on Thursday morning as he was laid to rest.

The service was historic for being led by a living pope, after Benedict became the first pontiff in centuries to resign in 2013.

Pope Francis made little direct reference to his predecessor in his sermon. He spoke on Thursday mainly about devotion to God and trust in the Lord.

Only at the very end did the 86-year-old Argentinian pontiff say in front of the wooden coffin: "Benedict, faithful friend of the Bridegroom, may your joy be complete when you hear his voice now and forever!" Jesus is often referred to as the Bridegroom in the Catholic Church.

According to the Italian news agency ANSA, 300 bishops were among the guests.

In a touching moment, Georg Gänswein, the cleric who served as Benedict XVI's personal secretary and confidant during his papacy, bent over the coffin to kiss it after it was brought out onto St Peter's Square. Gänswein was perhaps the closest person to Benedict in his final years. He served as the pope's private secretary after Benedict's election in 2005 after previously working with him in Rome.

After the service, the late pope was buried in the crypt of St Peter's Basilica. The public was excluded from this part of the funeral service.

Benedict XVI died at the Vatican on New Year's Eve at the age of 95. He had been lying in state in St Peter's Basilica since Monday so that the public could pay their respects.

It was also announced on Thursday that Bishop Rudolf Voderholzer will look after the personal estate of the deceased church leader as director of the Pope Benedict XVI Institute. Open lawsuits against the late pope emeritus, now transferred to his estate, remain up in the air.