Roman Basilicas

Roman basilicas were one of the major successes of Roman construction and architecture. Through an optimised use of building methods, materials, arches and vaults the Romans were capable of constructing these large area buildings for public use such as law courts and offices.

Livy tells us there were no Roman basilicas before the year 210BC (Livy book XXVI,27). The first basilicas entered Roman public architecture during the 2nd century BC, after the conclusion of the Punic wars against Carthage and the increased dominance across the Mediterranean.

The Basilica replaced earlier “Atria”, which were private buildings involving a central courtyard surrounded by a variety of single rooms – like the peristyles of richer Pompeii villas. The atria in the Forum were used for a variety of services such as the meeting of merchants and guilds, law courts or storage of legal documents. For example:

• Atrium Libertatis was used for the proceedings involving the freedom of slaves.
• Atrium Titium was near the senate and had a political role
• Atrium Regium was linked to the head priest “Rex Sacrorum” and had a religious function.

There are many noteworthy basilica examples across the Roman world. The Roman Forum contained at least 6 basilicas, also including the

• Porcia – the first Basilica, built by Cato the Censor in 184BC
• Fulvia & Aemilia – 170BC – later called Aemilia since they provided for its restoration. The only surviving Republican basilica
• Opimia – Built in 121BC at the north end of the Roman forum. Probably demolished by Tiberius.
• Iulia – built by Julius Caesar in 55BC replacing an earlier basilica Sepronia. The Basilica Iulia had a central nave and two double side aisles ie 5 parallel sections.
• Ulpia – Built by Emperor Trajan when Rome was already well into the Imperial phase.
• Maxentius: See this youtube reconstruction video. Notice how it feels similar to St Peter’s, though below we describe how St.Peter’s evolved further.

In the later Empire, Basilicas were used by the Christians as sites for reunions and prayer and the basilica name therefore gained a renewed religious meaning, rather like the Atrium Regium. Several were erected in the late Empire (ie 4th century or later)

A couple of good examples include:

• Saint Peter’s
• Santa Maria Maggiore
• Santa Maria in Trastevere

The layout of ancient Roman Basilicas

The layout of the basilicas was to have a large central isle flanked by two isles, one to either side of the main one. The central isle would often be taller than the sides so that windows in the top section might let light into the building.

An apse at the end, possibly raised from the floor level, would provide a focal point to public reunions for example with seating for judges or other high ranking persons. A good sense of this can be achieved from the remains of the basilica at Pompeii shown below.

An architectural phenomenon with the most profound meaning!

The Christians made use of the apse for the altar (to the supreme judge). The apse itself was set off from the rest of the building and the congregation, by way of a large triumphal arch. It is enticing to think that this arch could be considered the descendant of the Tigillum Sororium, the archetypal arch : Itself the symbol of a yoke, since the earliest days of Rome it was an accessory for the ritual atonement of soldiers’ sins at war. 

The walls would be supported by rows of columns into which the weight of the walls would be channeled by arches. The use of columns and arches enabled the overall floor area to be very significant, especially if arch and vaulting methods were employed as in the basilica of Maxentius in the Forum.

The roof would be held by wooden trusses and covered in terra-cotta tiles. The width of the central isle would be therefore limited by the possibility of building sufficiently wide roofs without the danger of them caving in which in great degree would be limited by the length of the wooden beams available. This limitation was obviated in buildings such as the Colosseum where large areas were spanned with the use of lightweight materials such as sails, but this was clearly not a viable solution for permanent roofs in buildings such as the basilica.

Basilicas of Rome

Given the strong focus on public life in ancient Rome it would be unusual for any city of the empire to be without its own basilica in which to run state bureaucracy and business.

Famous basilicas the remains of which may still be visited include the basilica Iulia, Ulpia and of Maxentius in the Roman Forum.

Ecclesiastical basilicas which still give a strong sense of the structure and architecture include:

• the basilica of Saint Paul outside the walls of Rome (the architecture dates as far back as Emperor Constantine but it was actually rebuilt after a devastating fire in the 19th century)
• The basilica of Santa Maria Maggiore
• the basilica’s on the Aventine hill such as Santa Sabina, using many remains from the temple of Juno: Juno Goddess.
• Possibly the most famous is St. Peter’s Basilica, but the actual structure has little in common with ancient Roman basilicas as architects of the renaissance and baroque periods changed the focal point of the building towards the centre, added domes and made strong use of references to classical buildings such as the Pantheon.

What was a “Basilica” exactly?

The name Basilica actually came from Greece. It was used to mean a large rectangular building with a central nave and one or two side aisles. The large size was achieved by a combination of the greatest achievements of Roman engineering and construction methods; including columns of extraordinary size, arches to join them and a combination of Roman building materials also including concrete. Second and third floors could be built directly above the ground floor to achieve bewildering volume and size.

They could be used for a variety of purposes; in many ways they could be considered as covered forums. The graffiti all over the walls of the Basilica at Pompeii shows how they were likely to be highly frequented public spaces.

What were Roman Basilicas used for in ancient Rome?

There were public and private Basilicas, the private ones built by extremely rich individuals for personal use as part of a palace or collective use. The public Basilicas are the best known and some achieved incredible sizes. Their earlier use was for public spaces such as law courts or offices. A number of them were dedicated and named after particular types of trade and merchandise.

In later periods the basilicas were increasingly used for religious purposes and it is for this reason that we can still see buildings such as Santa Maria Maggiore, built in Roman times, albeit towards the later part of the empire it is still in use today.