Pope Francis died of a stroke yesterday at the Vatican aged 88.
His funeral is to be held on Saturday in the presence of worshippers and dignitaries before a conclave of cardinals is convened to elect a successor.
Here's what we know about the circumstances surrounding the Pope's death and what is to follow.
Fatal stroke
Pope Francis was admitted to Rome's Gemelli hospital on 14 February with bronchitis, which later turned into double pneumonia that almost killed him twice.
He left hospital on 23 March and was due to undergo a strict two-month convalescence period.
But the Argentine made a series of impromptu public appearances, looking increasingly weak.
He started to feel unwell at around 5:30am yesterday morning and was promptly attended to by his team.
More than an hour later he made a gesture of farewell to his ever-present nurse, Massimiliano Strappetti, and slipped into a coma, the Vatican's official media channel said.
His time of death was given as 7:35am, local time.
The Vatican announced his death afterwards.
According to a death certificate released by the Vatican, Francis died of a "cerebral stroke, coma, irreversible cardiocirculatory collapse".
Read more:
Cardinals to meet after death of Pope, plan for funeral
Faithful will say their goodbyes, as Pope did on Easter Sunday
Who might succeed Pope Francis? Some possible candidates
Francis brought 'unique humility' to the role - President Higgins
Lie in state
Pope Francis's body was displayed yesterday evening in an open coffin, which he previously ordered should be of wood and zinc, in the chapel of Casa Santa Marta, the Vatican residence where he lived.
In photos published by the Vatican, Francis was seen dressed in his red papal vestments, a mitre (a tall, pointed hat) on his head and had a rosary between his fingers.
His body is to be transferred to Saint Peter's Basilica tomorrow at 7am Irish time to lie in state.
People will be able to pay their final respects to Pope Francis from tomorrow through Friday, the Vatican said in a statement.
Catholic faithful and the general public will be able to visit from 11am local time to midnight tomorrow, 7am to midnight on Thursday, and 7am to 7pm on Friday.
Funeral
Francis's funeral will take place at 9am Irish time on Saturday in the square in front of St Peter's Basilica.
The coffin will then be taken inside the church and from there to the Rome basilica of Santa Maria Maggiore for burial.
His funeral service will be presided over by Cardinal Giovanni Battista Re, the 91-year-old dean of the College of Cardinals.
World leaders and faithful from across the globe are expected to flock to Rome to attend the ceremony and pay their respects to the leader of the world's 1.4 billion Catholics.
US President Donald Trump, Ukraine's Volodymyr Zelensky and France's Emmanuel Macron are among those who said they would attend.
Taoiseach Micheál Martin is also expected to attend the Pope's funeral.
Conclave
Francis' death has set in motion ancient rituals, as the church started the transition from one pope to another, including the breaking of the pope's "Fisherman's Ring" and lead seal, used in his lifetime to seal documents, so they cannot be used by anyone else.
The starting date of the conclave, during which 135 so-called "cardinal electors" will choose Francis's successor, is not yet known.
But it should begin no less than 15 days and no more than 20 days after the death of the Pope, thus between 5 May and 10 May.
The cardinals will meet in the Sistine Chapel, a Renaissance jewel adorned with Michelangelo's celebrated frescoes, and hold four ballots a day, two in the morning and two in the afternoon, until one candidate wins two-thirds of the votes.
At the end of each session, the ballots are burned in a stove by the chapel, releasing smoke above the Apostolic Palace as the world watches.
If black smoke billows from a chimney overlooking St Peter's Square, the vote has been unsuccessful.
White smoke signals a new pope has been elected.
At present there is no clear frontrunner to succeed Francis.
