Hours after his death Saturday night from an acute fever and organ failure, his embalmed corpse was placed on a plinth in the Vatican, his papal staff under his arm, and displayed to cardinals, prelates and dignitaries.
This morning, it will be moved to St. Peter's Basilica to be viewed by an estimated two million pilgrims over the next three or four days, before a funeral that will likely be held Thursday or Friday.
Throughout the day, the image of the pontiff's ashen corpse, clothed in bright red robes, its hands clutching a rosary, was broadcast around the world on television, an unprecedented electronic update to a centuries-old custom.
In an unprecedented flourish, senior Vatican officials and many conservative Roman Catholic figures have taken to calling him "John Paul the Great," a title that has previously been applied only to popes who have become saints.
The title was used most prominently yesterday by Cardinal Angelo Sodano, the Vatican's top clerical official and a leading conservative, who had it in the text of a homily for his mass at St. Peter's Square, which was distributed to the world's news media. But he did not actually utter the phrase when he delivered the homily.
Yet even as conservatives appeared eager to declare John Paul a saint, the jockeying had already begun to lobby for reform, in a more liberal or an even more orthodox direction, in the selection of the next pope.
That process will begin officially this morning, when the majority of the 117 cardinals eligible to elect a pope meet in the Vatican to arrange a date for the beginning of the conclave that will select the new pope.
The secret and complicated process, which must begin at least 15 days and no more than 20 days after the Pope's death, is likely to face intense pressure both from within the intensely factionalized church and from world leaders who have interests in the church's political positions.
Desmond Tutu, the former Anglican archbishop of Cape Town who is known for his leadership in South Africa's anti-apartheid movement, was one of first to leap overtly into the fray yesterday.
"I hope the cardinals will follow the first non-Italian by electing the first African pope," he declared.
The prospect of the first dark-skinned pope in centuries was tempered by the fact that most African cardinals are deeply conservative on social issues, perhaps more than John Paul himself, and there is pressure from cardinals and lay officials in the Americas and Europe to select a pope who will be more tolerant, for example, of a stronger role for women in society and the church.
Yesterday's accolades, however, came not just from conservative quarters but from leaders across the political spectrum who admired John Paul's diplomatic work. Even Cuban President Fidel Castro issued a statement of praise for the Pope, who visited the island in 1996.
"Humanity will preserve an emotional memory of the tireless work of His Holiness John Paul II in favour of peace, justice and solidarity among all people," the Communist leader wrote.
Leaders of competing religions were also eager to praise the legacy of the first Pope in modern history to meet with Jewish and Muslim leaders and to make efforts to atone for the church's earlier support of anti-Semitic positions.
"The Jewish people will remember the Pope, who bravely put an end to historic injustice by officially rejecting prejudices and accusations against Jews," Israeli President Moshe Katsav said in a broadcast interview.
Sheik Salah Keftaro, a prominent Syrian Islamic cleric, said: "Muslims and Christians alike have lost the Pope, and we are in a deep sadness for his loss."
In one touching tribute, the people on the earthquake-devastated Indonesian island of Nias, a pocket of Christianity in the largely Muslim country, held a special mass at their cathedral to commemorate the Pope as they cleaned up the damage from this month's magnitude 8.7 earthquake.