Where was Roman catholic church built?

The first foundation of what was originally called the Latin or Western Christianity and later came to be called the Catholic Church were laid by Tertullian, a Roman who lived in Carthage in present day Tunisia in what was then in the Roman Province of Africa. It became the religion of the western part of the Roman Empire. The religion of the eastern part of the Roman Empire was Greek or Eastern Christianity, which later became the Orthodox Church.
The main centres of Catholicism became Rome and Milan because the former was the seat of the Bishop of Rome and the latter was the Imperial capital of the Roman Empire and attracted many scholars and theologians. St Ambrose, one of the "fathers of the church" was the Bishop of Milan. St Augustine, whose work became the centrepiece of Catholic theology, was a Roman from Thagaste, also in Roman Africa and in present day Algeria.He converted to Christianity and did his theological work in Milan.