Tens of thousands of people are expected to pay their respects to retired Pope Benedict XVI when his state funeral begins tonight at the Vatican.
He died on New Year's Eve at the age of 95, over a decade after stepping down due to illness.
Pope Francis will preside over the burial on Thursday, marking the first occasion a Pope will be buried by his successor.
As the sun rose over the Vatican, a line was already developing on the outside of St Peter's Square.
In 2013, Benedict XVI became the first Pope in 600 years to resign, claiming ill health.
His remains will be displayed in an open coffin at St. Peter's Basilica for three days, with guests able to pay their respects until 7 p.m. each evening.
The Pope Emeritus will be put to rest in the graves under the Basilica after his burial at St Peter's Square.
On Sunday, the Vatican revealed images of the body, which was clothed in scarlet papal mourning garments and a gold-trimmed mitre.
Tributes have been pouring in from all around the world, and the burial is anticipated to gather tens of thousands of people.
Pope John Paul II's burial in 2005 brought an estimated four million people to Rome, making it one of the greatest Christian gatherings in history.
According to Vatican spokesperson Matteo Bruni, Benedict requested that the funeral be simple.
The guest list has not been made public, although the Vatican has stated that it would include representatives from Italy and Benedict's home country of Germany.
Following the death of his "dearest" predecessor, Pope Francis paid respect to him.
US President Joe Biden honoured the former Pope's "lifetime of commitment to the Church", while Italian Prime Minister Giorgia Meloni greeted him as "a wonderful man whom history will not forget".
In Brazil - the largest Catholic nation in the world - incoming President Luiz Inácio Lula da Silva said he wanted "comfort to the faithful and fans of the Holy Father".
Pope Benedict was a divisive figure, with some accusing him of neglecting to address charges of clergy sexual abuse.