Cardinals will convene on Tuesday to determine the date for Pope Francis’s funeral, beginning the formal Vatican process that will lead to the election of a new Catholic leader within three weeks.

Pope Francis, who led the world’s 1.4 billion Catholics, passed away at his residence in the Vatican on Monday at the age of 88, after suffering from a stroke. He had recently been recovering from double pneumonia, which had required a five-week hospitalization.

Tributes have poured in from across the globe for Pope Francis, a liberal reformer who assumed the papacy in 2013 after the resignation of German theologian Benedict XVI.

His home country, Argentina, declared a week of national mourning, while a number of countries began three days of mourning on Tuesday, an exceptional gesture for a foreign religious figure.

Heads of state and royalty are expected to attend his funeral at St. Peter's Basilica.

Cardinals to prepare for conclave to elect new pope

According to the Apostolic Constitution, the funeral will be held between the fourth and sixth days after the pope’s death, suggesting it will occur between Friday and Sunday.

Final details will be determined by the cardinals, who have been summoned to the Vatican for the first of several general congregations starting at 9:00 am (0700 GMT) on Tuesday.

Cardinals from around the world are invited to these meetings, though only those under the age of 80 will be eligible to vote in the conclave for a new pope.

The conclave itself must begin no earlier than 15 and no later than 20 days following the pope’s death.

Francis’s humility reflected in burial arrangements

The Vatican confirmed that Pope Francis’s body was moved to the Santa Marta chapel on Monday evening, and his apartment has been formally sealed.

His remains will be transferred from the Santa Marta residence to St. Peter’s Basilica on Wednesday to lie in state.

In keeping with his modest lifestyle, Francis requested a simple tomb bearing only his Latin name, "Franciscus."

He will be buried at Rome’s Santa Maria Maggiore basilica, making him the first pope in over a century to be interred outside the Vatican.

The Vatican-issued death certificate stated that Pope Francis died of a stroke, which led to a coma and “irreversible” heart failure.

Although discharged from Rome’s Gemelli hospital on March 23 with instructions to rest for two months, he continued to appear in public.

On Easter Sunday, despite visible fatigue, Francis greeted crowds in St. Peter’s Square from his popemobile.