[5] Likely origins are Celtic root lut- meaning "a swamp or marsh" + suffix -ecia,[6] It survives today in the Scottish Gaelic lòn ("pool, meadow") and the Breton loudour ("dirty").

[5][7] Traces of Neolithic habitations, dating as far back as 4500 BC, have been found along the Seine at Bercy, and close to the Louvre.

They had traditionally placed the main settlement on the Île de la Cité, where the bridges of the major trading routes of the Parisii crossed the Seine.

Critics also point out the lack of archaeological finds from the pre-Roman era on the Ile de la Cité.

In his account of the war in Gaul[10] Caesar wrote that, when the Romans later laid siege to Lutetia, "the inhabitants had burned their structures and the wooden bridges which served to cross the two branches of the river around their island fortress," which appears to describe the Île de la Cité.

[11] Proponents of the Ile de Cité as the site of the Gallic settlement also address the issue of the lack of archaeological evidence on the island.

It was fought near a river, which some historians interpret as the Seine, and others as the Yonne; and near a large marsh; a feature of the countryside near both the Île-de-la-Cité and Narbonne.

[11][12] The first traces of the Roman occupation of Lutetia appeared at the end of the 1st century BC, during the reign of the Emperor Augustus.

[16] The Cardo Maximus met the Decumanus, or main east-west street, located at modern rue Soufflot.

One of the most striking archeological finds from the early period is the Pillar of the Boatmen which was erected by the corporation of local river merchants and sailors and dedicated to Tiberius.

The mid third century brought a series of invasions of Gaul by two Germanic peoples, the Franks and the Alemanni, which threatened Lutetia.

Portions of the left bank settlement, including the baths and amphitheatre, were hurriedly abandoned, and the stones used to construct ramparts around the Île de la Cité.

[20] A new civic basilica and baths were built on the island whose vestiges can be seen in the archeological crypt under the Parvis in front of Notre-Dame Cathedral, Place John Paul II.

In 357–358 Julian, as caesar of the Western empire and general of the Gallic legions, moved the Roman capital of Gaul from Trier to Paris.

[citation needed] The end of the Roman Empire in the west, and the creation of the Merovingian dynasty in the 5th century, with its capital placed in Paris by Clovis I, confirmed the new role and name for the city.

[24] The civic basilica, essentially the town hall, occupied the east of the forum, It contained the courts where political, social and financial issues were discussed and decided.

[citation needed] It had a stage and backdrop used for the presentation of plays, along with a larger space suitable for the combat of gladiators and of animals, and other large-scale festivities.

In the early 4th century its stone was used in the construction of the fortress on the Île de Ia Cité, at a time when the province was threatened by barbarian invasion.

[25][26] A bus depot was planned to be built on the same site, but a coalition of notable Parisans, including Victor Hugo, insisted that the vestiges be saved.

They would cross the courtyard to the entrance of the baths, change their clothes, and go first into the caldarium, a hot and steamy room with benches and a pool of heated water.

After a period of time there, bathers would move to the frigidarium, which had a cold-water pool and baths, or to the tepidarium, which had the same features at room-temperature.

They were free of charge, or accessible for a small fee, and contained not only baths but also bars, places to rest, meeting rooms and libraries.

[33] The residential streets of Lutetia, unlike the boulevards, were irregular and not as-well maintained as they were the responsibility of the home-owners, not the city.

Additionally, remains of private houses dating from the reign of Augustus (27 BC – 14 AD) containing heated floors were found.

The source of the aqueduct was in the hills outside the city at Rungis and Wissous in the present department of the Essonne where a collection tank was excavated.

The aqueduct was built in the second half of the 1st century AD mainly to supply the monumental public baths of Cluny.

[36] Beginning in 307 AD, the increasing number of invasions of Gaul by Germanic tribes forced the Lutetians to abandon a large part of the city on the left bank, and to move to the Île de la Cité.

[38] In the later years of the Empire, when the pressure of invading Germanic tribes led to the abandonment of the old monuments, a new necropolis, named for Saint-Marcel, was established near the modern Avenue des Gobelins and Boulevard du Port Royal, along the Roman main road leading to Italy.

The tombs at Saint Marcel contain a variety of ceramic and glass objects from the workshops of the city, placed at the foot of the deceased.

Archaically, it was not unheard of for French people, particularly poets and musicians, to use the name Lutèce as a poetic or literary replacement for Paris as we know it.