The ancient city of Jerash is proud of being the city where the population has continued for 6500 years. In the pre-Roman era, specifically during the reign of Ptolemy III, Jerash was a prosperous city. Then it was occupied by Alexander Jannaeus, where it remained under Jewish rule until the Roman commander Pompey occupied Syria and Palestine in the middle of the first century BC. During the Roman era, Jerash was famous for its many huge temples, which became an example of an ancient Roman city. After the end of persecution and the conversion of the Romans to Christianity, the city began to gain fame for its numerous and large churches. Today, there are twenty churches in Jerash.
Jerash has been inhabited since the Bronze Age, and it flourished during the Ptolemaic period (246-221 BC) and then the Jewish Kingdom (102-76 BC) until it was captured by the Romans in the first half of the first century BC, and it was included in the Ten Cities Alliance (Decapolis) and enjoyed stability and peace for six years under the rule of the Romans until the fourth century AD. Some believe that its proximity to the iron mines in Ajloun was one of the reasons for its importance at the time.
The engineers have excelled in the design and implementation of the city; The Roman design made the main street the center of the city, with two rows of columns on its sides, and intersecting with two other streets to control the movement of the whole city. The large, paved market square, surrounded by imposing columns, was the heart of the city. It was teeming with temples, markets, public baths, grandstands and columns. This Roman city was surrounded by impregnable walls, and contained a spring of water known today as Ain Kairouan to meet its water needs. Among the most prominent monuments: the pond, the small amphitheater, the great amphitheater, the mermaid fountain known as the path of the nymphs, the Temple of Artemis, and the Temple of Zeus. Jerash was also famous for its structures in the pagan Roman era.
History does not mention when Christianity began to spread in the city of Jerash, but it is certain that it spread early in the Christian era. During the Roman persecution of Christianity for three centuries, he made Christians perform their rituals of worship in secret, until the era of persecution ended and Christianity took its place in the state and society, and it continued for nearly two and a half centuries, i.e. the middle of the fourth century until the beginning of the seventh century. When the era of persecution ended, churches abounded in them. About twenty churches were found in the city of Jerash today, while there may be other churches that are still under the dirt and ruins. The most important of these churches are:
- The cathedral church: It consists of the temple area and its three naves. So far, it appears that it is the oldest church in Jerash and dates back to the middle of the fourth generation. The people of the city were celebrating the miracle of Cana of Galilee, considering it the official feast of their city.
- The Church of St. Theodore (494-496 AD): It is located near the cathedral, and some writings mention that the site of the church was a dump, and the church was built in that location and became the pride of the city during the era of Bishop Enaus.
- Near the Church of Theodore, the Martyr, and to the south of it, a small church was erected, and the inscription on the mosaic states that it was established “to commemorate the comfort of the souls of those who donated its construction and in honor of the Blessed Virgin Mary.” It is likely that this small church was established in the sixth century.
- To the west of the Church of Theodore the Martyr, and close to it, three churches were erected in the year 529-533 AD: the Church of John, the Church of St. George, and the Church of St. Cosmas and Damianos, and each of them has a door that leads to the other churches. The Church of John is in the middle of the three churches. It is distinguished from the other two churches in that it was built in the form of a circle within a square, and it seems certain that its design came as a miniature of the Bosra al-Sham Cathedral, which was established a few years before it. Its floor is covered with mosaics that reflect different geometric shapes, animals and birds. The mosaic of the Church of Saints Cosmas and Damianus depicts the benefactor Theodore and his wife Georgia, as well as other benefactors. The writing in it mentions that it was inaugurated in the year 533. It is worth noting that Saints Cosmas and Damianus were born in the Roman Arab province, and they were doctors, and they were martyred during the reign of Emperor Diocletian in the year 287.
- Procopius Church: It is located on the eastern side of Jerash. It was built by Procopius, a military officer at his own expense, in the year 526-527 AD.
- The Church of Saints Peter and Paul in the southwestern part of the city.
- The Church of Archbishop Janisios, which was built in 611 AD, and is located to the west of John Church. It was the last church built before the Arab conquest.
All of these churches are clear evidence that the city was blessed with prosperity and life. The Persian invasion in 614 destroyed many churches. After the Arab conquest, the whole country was subjected to a number of major earthquakes, especially the earthquake in 747, which destroyed many cities and villages.