The Île de la Cité was the centre of ancient Lutetium, medieval Paris and the contemporary capital.
The Île de la Cité is formed by two meanders of the Seine. It was inhabited by the Parisi Gauls starting in the second century B.C. and was occupied by Jules Caesar’s Romans in 52 B.C. It covers seven hectares at the crossroads of the Seine and the major Roman road called the cardo (today the corner of the Rue Saint Martin and the Rue Saint Jacques). In Roman times, this road crossed the river thanks to two wooden bridges on piles: the Grand Pont (today’s Pont Notre-Dame) and the Petit Pont.
The Île de la Cité was the cradle of Gaul’s Lutetium, and the birthplace of Roman river commerce, which, from the 1st century to today, made the Parisian boaters (in French nautes) wealthy, as seen in the Nautes Pillar, showing images of Romans and Gauls. It is kept in the Musée de Cluny.
On the western tip of the downstream side, the island was fortified in the late 3rd century B.C., after which it became an imperial and administrative residence. It is there that Julian the Apostate was declared emperor by his soldiers in 359-360. Another Roman emperor, Valentinian I, would live there in winter 365-366. In 508, Clovis, King of the Franks, set up the seat of his kingdom there. The site would remain a royal residence until the Louvre was built under Philippe Auguste’s reign in the 12th century. It was also on the island that Saint Louis would build Sainte Chapelle between 1242 and 1248. The chapel was designed as a shrine for the crown of thorns. Today, the island is home to Paris’s Palais de Justice. The Palais de Justice is home to a few ruins of the former royal palace: the Tour Barbec, the Tour d’Argent, the Tour de César, the Tour de l’Horloge, the Salles des Gardes and the Conciergerie.
The eastern tip, on the upstream side, would see a rise in Christianity, which came to Paris in the 3rd century thanks to the bishop Saint Denis, and grew in influence in the 4th, 5th and 6th centuries. In this capital, which would take on the name of its inhabitants, the Parisis, a holy city would be built on the banks of the Seine, including a Cathedral-Church, a baptistery, a bishop’s palace, a canon cloister with bishop’s schools, and the Hôtel-Dieu hospital for the sick and impoverished.
In the 9th century, smaller churches were built on the parvis in front of the cathedral to protect relics from Norman pillages. In around 1100, the Ile de la Cité had a population of around 3,000, which included the clerks, ecclesiastical school masters and servants of the Royal Palace.
In the 12th century, Maurice de Sully, who was bishop of Paris at the time, began construction on a new cathedral on the site of two former places of worship: Notre-Dame and Saint Stephen. The Rue Neuve was opened along the future cathedral’s axis, crossing through a maze of alleys, closely-built wooden houses, and seventeen chapels. This new street made is possible to transport construction material and connect the cathedral to the existing north-south thoroughfare.
The "Parvis Notre-Dame", which was expanded in the 17th century, was cleared of all houses and buildings and arranged in its current configuration by Baron Haussmann in the 1860-1870. The cobblestones show the names of former buildings (including Saint Stephen’s cathedral (cathédrale Saint-Etienne)). The archaeological crypt houses the ruins discovered during excavation in 1965-1967.