When the cardinals meet for the conclave, they gather in the Sistine Chapel. All cardinal electors must swear an oath of secrecy and vote by secret ballot. A two-thirds majority is needed to elect a new pope, and campaigning is part of the process, though it should not appear so.

A papal conclave, the election of a new pope, tends to begin 15-20 days after a papal vacancy. Black or white smoke indicates each day's decision.

The Vatican’s cardinals’ assembly, known as the General Congregation, has chosen May 7 as the starting date for the highly secretive election that will choose the next pope, the Holy See said on Monday.

Pope Francis' funeral brought world leaders, monarchs, and hundreds of thousands of people to Rome on Saturday to bid him farewell in a ceremony of breathtaking spectacle that offered age-old Catholic funeral rites and touching moments of personal grief.

For Catholics and non-Catholics alike, fascination with the pope and rituals such as the papal conclave continue to transfix and intrigue.