It was the emporium of the powerful Cuma.

Then with the arrival of fugitives from Samos in 530 BC. it took the auspicious name of Dicearchia (“right government”), and began its urban development.

After the period of Campanian domination, in 338 it fell under the influence of Rome, but following Hannibal's attempted conquest in 215 BC. that the commercial and military importance of the entire Phlegraean gulf was understood. Thus Puteoli (“small wells”) became the most important landing place in the Mediterranean. It was called “Delus minor” and “Litora mundi hospita”. The arts of glass, ceramics, perfumes, fabrics, colors and iron found widespread diffusion, due to the presence of local workers educated in Phoenician, Hellenistic and Egyptian traditions. Thanks to the port, Puteoli came into contact with other cultures and civilizations. In 61, Saint Paul stayed there for seven days and already found a community of Christians there. The city prospered as long as the port responded to the needs of Roman trade, but suffered a serious blow with the opening of that of Ostia.

With the accentuation of descending bradyseism, which submerged the port works, and with the fall of Rome (476 AD), Puteoli became a small fishing center and, in the Middle Ages, the Campi Flegrei were only the destination for short spa stays. Only after the eruption of Monte Nuovo in 1538, Pozzuoli began a slow socio-economic-urban recovery, thanks to the work of the Spanish viceroy Don Pedro Alvarez de Toledo.
 
Arriving from Naples to Pozzuoli you come across the Church of San Gennaro in the place of the saint's martyrdom. A few steps away is the entrance to the Solfatara crater, the most interesting volcano in the area from a geological, faunal and botanical point of view.

After three kilometers you reach the Flavian Amphitheatre. From here you continue in the direction of Corso Terracciano and come across the ruins of the so-called Temple of Neptune, a 1st century spa building, and those of the Nymphaeum of Diana of which the circular base and part of the elevation are preserved. If you continue along via Carlo Maria Rosini you arrive at the old city of Pozzuoli. The road crosses a splendid panorama and passes in front of the entrance to Rione Terra, the ancient historic centre of Pozzuoli perched on a tufaceous terrace overlooking the gulf, 33 meters above sea level. The Roman Puteoli settlement extends into the belly of the yellow tuff formation, because, on various levels, that site was continuously inhabited from Roman times until 1970, when the continuous, increasingly violent telluric movements led to its depopulation and abandonment. It lasted for decades, until 1993, when, with the reconstruction of the historic buildings, archaeological excavations began in full swing, bringing the underground Roman settlement to light. A heritage of extraordinary historical-archaeological interest, which can be visited since 2014, when it was decided to open it to the public.
The grandiose Puteolan acropolis culminated in the Temple of Augustus, which was brought to light after the fire of the cathedral (16-17 May 1964): it is the Capitolium of the city of the republican age. At the behest of the rich Pozzuoli merchant Lucio Calpurnio, it was rebuilt by the architect Lucio Cocceio Aucto in the Augustan age in beautiful Corinthian forms. Then it was converted into a Christian church between the 5th and 6th centuries and baroqued under the episcopate of Martino de Leòn y Càrdenas (1634). Its remains were incorporated into the construction of the Cathedral of San Procoloin the 17th century, dedicated to the martyr Procolo when the citizens were forced to retreat to the rock to defend themselves from the attacks of the barbarians.
Among the important works of art in the Pozzuoli Cathedral there are also three paintings by Artemisia Gentileschi: San Gennaro in the amphitheater of Pozzuoli, Santi Procolo and Nicea and Adoration of the Magi.
 

The Church of the Assumption, in via Castello on the Rione Terra dock, is small, simple and linear and evokes the great maritime tradition of the fields: it was built in 1621 in honor of the purification of the Madonna and a tsunami destroyed it in 1876.

In Pozzuoli the Romans built the most important port of the empire: a lively commercial port as still attested by the nearby macellum, the public market, better known as the Temple of Serapis.

Among the other churches in Pozzuoli, we should mention that of the Purificazione in via Marconi, built in 1702, with a single nave. The church of the Archangel Raphael in via Rosini dates back to the mid-eighteenth century and was built on the site of a small convent dedicated to Saint Catherine of Alexandria. The church of Purgatory at the Tellini ramps was built by the Confraternity of the Good Death in 1639. The church of Sant'Antonio, in via Pergolesi, dates back to 1472 and was commissioned by Don Diomede Carafa, Duke of Maddaloni. It was restored several times starting from 1540 when, on the initiative of Don Pedro de Toledo, it was embellished with two valuable stoups. The church of San Vincenzo Ferrer is also known as "Gesù a mare" and dates back to the first half of the 16th century and was entrusted to the Dominicans until 1806 and then entitled in 1847: it is a Latin cross with side chapels.
In Piazza della Repubblica there is the Church of Santa Maria delle Grazie, the oldest parish in Pozzuoli after that of the Duomo. Its events are linked to bradyseism and the eruption of Monte Nuovo in 1538, an event that damaged the small existing church. It should be remembered that due to the effect of descending bradyseism it remained flooded, together with the village, and was demolished and then rebuilt with an elegant neo-Renaissance style.