Veroli is a little town in the zone of Frosinone, (region of Lazio, 80 km distant from Rome,) situated on one of the summits of the Ernici mountains, from where there is a magnific panorama allaround. The town has very ancient origins: the Ernici, one of the ethnic groups of Latium, settled in this area around the 12th century B.C. and founded the town in strategic position.

Of the ancient town remained until our days a large part of the walls, forming a polygon, built during Roman times and subsequently modified in the course of the Middle Ages. Later, Veroli, like all the towns of Latium Novum, fell under Roman rule. Allied with Rome during the social war, Veroli gained a certain degree of administrative independence when it became a municipality. Evidence of the period of the alliance with Rome are the Fasti Verulani (lst century), a special Roman calendar found in the courtyard of one of the houses in the centre. This calendar shows only the first three months of the year, each month being broken down into fasti (favourable days), nefasti (unfavourable days). From the 4th century on there is evidence of the stable presence of a large Christian community.

In the 9th century, during the invasions of the Saracens, Veroli began to play a significant political and military role, as it was situated along an important axis. In 877 the town was plundered by the Saracens. In the meantime, and more precisely in 743, Veroli became the bishop's see, thereby falling once again under the control of Rome, but this time as the see of the tempora1 power of the Popes. The battle against Frederick II is evidence of Veroli's bond of loyalty to the Church. This is why the transfer of the Papacy to Avignon paved the way for the political crisis of Veroli. The Norman forays led to a new period of unrest. However, once the situation became more stable, the town, strategica1ly upholding the Papacy, played an important role of interposition between the South, under Norman control, and the North, under Germanic control. 

In the 16th century the Spanish troops, allies of the Colonna family, defeated the army of Pope Paul IV and conquered the town. Throughout the century, the town was ruled by cardinals, among whom Cardinal Quinones. Between the 16th and 17th centuries, the bond with the Church weighed heavily on the town: a group of enlightened bourgeois and noblemen, who upheld the Jacobin Republic in Rome, were slaughtered by rioting inhabitants.
The historical centre of Veroli is divided into three distinct parts:

• the upper part, the S.Leucio quarter, stretches northwards up to the stronghold bearing the same name;
• the middle part, developed around the central square, embraces numerous buildings of noble families erected around the cathedral of St. Andrea;
• the lower part, the Santa Croce quarter, situated ,on a slope, is characterized by its steep streets.

The 11th century cathedral was built over the main temple of the ancient Verulae. It was actually an extension of an early Christian building which later became a basilica with a nave, two side aisles, a transept, an apse and a crypt. According to the inscription on the modern façade this was restored in 1706 by desire of the bishop De Zaulis. The interior is in baroque style and is the result of works carried out in the 17th and 18th centuries which also eliminated the crypt. The central apse contains a wooden choir that dates to 1624. Two paintings by the Polish artist Taddeus Kuntz (1731-93): The disciples of the Baptist and The Martyr of St. Bartholemew are found on the left-hand side.

Equally important is the Giovardiana library (1773) which offers readers about 18,000 books, most of which are religious, however there are also many literary, historical and scientific works. The library also boasts precious manuscripts written on parchment, sixteenth-century works, engravings and drawings of the masters of the 16th and 17th century.
The history of the Church of St. Salome is very similar to that of the cathedral. The church dates back to the 13th century, but was rebuilt after the 1350 earthquake. In the 18th century, bishop De Zaulis began works on the façade, which however were completed by his successor Monsignor Tartagni in 1733. In 1209 the remains of the holy mother of the apostles Jacob the Major and John the Evangelist, patron of the town, were found where the church was sited. The apses are built into the slope on which the church was erected. The painting of the saint in one of the two apses is the work of Cavalier d'Arpino, while the painting of the sons has been attributed to G. Imparato. In the upper basilica dedicated to the patron St.Mary Salome, Monsignor Lorenzo Tartagni, bishop of Veroli, built the "Holy Steps" consisting of 12 marble steps (1740). By concession of Pope Benedict XIV, daily 100-day remission was gained by going up the steps on one's knees and once a month the same remission established by Pope Sistus V for the Holy Steps in S. Giovanni in Laterano. The eleventh step contains a relic of the Holy Cross.
St.Erasmus, a Romanesque church built over a monastery, is situated in via Garibaldi. This church was rebuilt in the 18th century (although it had already been modified in the 16th century), but the original three-arch portico façade, the apses and the bell tower were preserved. Originally it was most certainly a Benedictine monastery, perhaps founded by St. Benedict himself in the course of his journey from Subiaco to Montecassino. The painting Baptism of Jesus is on the aisle left-hand side, while another painting on request of Monsignor Giovardi, portraying Barbarossa and Alexander III, who met in Veroli in 1170 in the church of S. Erasmo to agree upon peace terms.
Belongs to the town of Veroli also the Abbey of Casamari built in 1005. During the 12th century the crisis within the Benedictine order put an abrupt end to the flourishing of the abbey and in 1140 Pope Innocent II gave it to the Cistercian monks. The holy buildings of this order of monks are characterised by a well defined architectural style (the gothic-Cistercian style) and strict rules according to which the plan has to be based on functionality.