Roman Baths: A Visit to the Thermae

The Roman baths, or thermae, were the most popular public buildings of the Roman world. Every city, town, and large village in the empire had at least one set of public baths, and the great imperial baths of Rome itself — the Baths of Agrippa, of Nero, of Titus, of Trajan, of Caracalla, and of Diocletian — were among the largest and most impressive buildings of the ancient world. The Roman bath was not just a place to wash; it was a kind of community center, where the Romans came to exercise, to read, to do business, to see friends, and to spend the afternoon. A visit to the Roman baths was a thoroughly social experience, and the famous image of the Romans spending hours at the baths is one of the most enduring of the ancient world.

This page is a guide to the Roman baths: their design, the sequence of rooms, the social life, and the modern legacy. It links back to the Roman Empire cluster, the Daily Life in Ancient Rome cluster, and the Colosseum page.

The History of Roman Baths

The Romans had used public baths since the third century BCE, but the great period of the Roman bath was the imperial era. The first of the great imperial baths of Rome was the Baths of Agrippa, built in 25–19 BCE by Marcus Agrippa, the son-in-law of the emperor Augustus. The baths were destroyed by the fire of 80 CE, but they were rebuilt and enlarged several times. The most famous of the imperial baths were the Baths of Caracalla (built 212–216 CE) and the Baths of Diocletian (built 298–306 CE), both of which were gigantic and elaborately decorated.

The Roman bath was a feature of every major Roman city. The bath at Bath (Aquae Sulis) in Britain, the bath at Trier in Germany, the bath at Ephesus in Asia Minor, and the bath at Pompeii (the famous Forum Baths and the Stabian Baths) are among the best-preserved baths of the Roman world.

The Architecture of the Roman Baths

The typical Roman bath was a symmetrical building with a sequence of rooms, each with a different function. The most important rooms were:

The apodyterium, the changing room. The Romans undressed here, hung their clothes on pegs or shelves, and left their belongings in the care of the bath’s slaves. Many apodyteria had benches along the walls and mosaic floors.
The frigidarium, the cold bath. The frigidarium was a large, airy room with a basin of cold water. After a hot bath, the Romans would plunge into the cold water to close the pores and refresh the body.
The tepidarium, the warm bath. The tepidarium was a room with a slightly warm temperature, used to acclimate the body to the heat of the caldarium. The tepidarium was often the most elaborately decorated room of the bath, with vaulted ceilings, marble walls, and intricate mosaics.
The caldarium, the hot bath. The caldarium was the hottest room of the bath, with a basin of very hot water (labrum) and a labrum for washing. The caldarium was heated by a system of hypocausts, the famous Roman underfloor heating.
The sudatorium or laconicum**, the dry hot room. The sudatorium was a small, very hot room, used to induce sweating before the cold plunge. The sudatorium was inspired by the dry saunas of the Etruscans and was a popular feature of the later baths.
The palaestra, the exercise yard. Many baths had an open-air courtyard or colonnade where the bathers could exercise, play ball, lift weights, or take a walk.

The Heating System

The Roman bath was heated by a system called the hypocaust, an underfloor heating system that circulated hot air from a furnace through a series of chambers under the floor. The floors of the bath were supported on small pillars of stacked tiles (pilae), and the space between the floor and the ground was the hypocaust, where hot air from a wood-fired furnace (the praefurnium) was circulated. The walls were also heated, by means of hollow tiles that carried the hot air up the inside of the wall.

The hypocaust was invented around the first century BCE and was a major engineering achievement. The system allowed the Romans to heat large buildings efficiently, and it was later adapted to heat the villas and palaces of the Roman elite.

The Bathing Ritual

A typical Roman bath sequence went something like this:

Exercise in the palaestra, including ball games, weightlifting, or wrestling.
Hot room (sudatorium or caldarium) to induce sweating.
Hot bath in the caldarium, often with oil rubbed into the skin to soften the dirt.
Strigil — a curved metal tool used to scrape the oil and dirt from the body.
Warm room (tepidarium) to acclimate the body.
Cold bath in the frigidarium to close the pores.
Rest and relaxation in the apodyterium, often with wine, food, and friends.

The Romans typically bathed in the afternoon, after the morning business and before the evening dinner. The bath was a social occasion, and a typical bath would take one to two hours.

The Roman bath was not just a place to wash; it was the social center of Roman life. The baths were a place to meet friends, to discuss business, to read the day’s news, to look at the women (or the men, depending on one’s taste), to gamble, to exercise, and to relax. The poet Seneca complained that the noise of the baths — the cries of the bathers, the shouts of the bath attendants, the sound of the water — was unbearable. The satirist Juvenal complained about the vanity of the bathers, who preened and postured in the changing room.

The baths were open to all free citizens, regardless of class. The emperor, the senators, the merchants, the artisans, the slaves, the foreigners, and the women all bathed in the same baths, although usually at different times of day. The bathing culture of Rome was a remarkable example of social equality in a deeply hierarchical society.

The Legacy of the Roman Baths

The Roman bath was one of the great achievements of Roman civilization. The system of hypocausts, the elaborate decoration, the social function, and the public access were all features that influenced later European culture. The Roman bath survived in modified form in the Islamic hammam and in the Turkish bath of the Ottoman Empire. The modern spa, the modern public bath, and the modern swimming pool are all in some way descendants of the Roman bath.

The ruins of the great imperial baths of Rome — the Baths of Caracalla, the Baths of Diocletian, the Baths of Trajan — are still among the most impressive ruins of the ancient world. The Baths of Caracalla in particular are a major tourist attraction, and they are the setting for operas, ballets, and concerts.