The Pope has the power to appoint bishops, to pass papal decrees and to guide the teachings of the Catholic faith. Though the Pope is said to have supreme power, he still refers to God.
They could excommunicate others.
I am not sure what your question is in reference to but the pope usually limits his powers of excommunication to heretics.
They were and still are the head of the catholic church
President plus prime minister, no pope.Israel has no pope. There are the Chief Ashkenazi and Chief Sephardi Rabbis, but these are more ceremonial roles than actual government offices. As concerns secular power, the majority of powers are vested in the Prime Minister as the Head of the Governtment and a few powers are vested in the President as the Head of State.
Are you referring to the Camerlengo? If a pope dies or resigns, until a successor Pope can be elected, the Camerlengo serves as the Vatican City's head of state. He does not have the powers of the pope, however, and is in now way considered to be a 'vice pope.' His main duties during this time is to arrange the funeral of his predecessor and the plan the conclave that will elect the next pope. The current camarlengo, appointed in December of 2014, is Cardinal Jean-Louis Tauran.
their economic powers declined and their church was handed over to the pope
Eisenhower, Patton, Field Marshall Montgomery, Churchill, Stalin and of course Churchill
Pope Paul VI was elected pope after the death of Pope John XXIII.
John Paul II
There is no pope named Pope XXIII. If you are referring to Pope John XXIII, he became pope in 1958.
Pope Francis is the reigning pope in 2013.
The current pope is Pope Benedict XVI.