Catholic churches are not tied to any one country but the head of the Catholic Church is Vatican states located in Italy.
Step-by-step explanation:
It is the oldest church in Vatican which had played a pivotal role in the development of western civilization. It practices the original Christian faith. It considers bishop to be the successor of saint peter. Catholicism is spread in Rome and it developed with new ideas in Rome.
Paganism and other beliefs were subdued due to the spread of Catholicism and under the great monarch called Constantine who embraced catholic faith, the whole Christianity religion flourished. It is the oldest and largest internationally recognized religious organization.