The dean cardinal will on Friday summon the cardinals to a general congregation, Lombardi said. That could come as soon as Monday, although the date is not yet fixed.

The cardinal-electors will then decide exactly when to hold the conclave, during which they will select a peer via paper ballot. The voting process will end when only when one cardinal gains two-thirds support.

After his resignation, Benedict, who cited the frailty of age as the reason he resigned, will no longer use the Fisherman's Ring, the symbol of the pope, Lombardi said. The ring will be destroyed, along with Benedict's papal seal, after his departure from office.