VATICAN CITY – The Vatican took the first steps of governing a Catholic Church without a pope on Friday, making some ceremonial and practical moves to formalize the end of one pontificate and prepare for the conclave to start the next.

Benedict XVI's 8 p.m. resignation Thursday opened what is known as the "sede vacante" or "vacant see" – the transition period between papacies when a few key Vatican officials take charge of running the church.

The dean of the College of Cardinals formally summoned his fellow "princes" of the church to Rome for an initial pre-conclave meeting Monday – something of a formality given that many of them are already here. But in a letter Friday, Cardinal Angelo Sodano also made clear that the conclave date won't be set until they have all arrived, meaning it may still be some time before a date is settled on.