Cenabum was a Gallic stronghold, one of the principal towns of the tribe of the Carnutes where the Druids held their annual assembly. It was conquered and destroyed by Julius Caesar in 52 BC, then rebuilt under the Roman Empire. The emperor Aurelian rebuilt the city, renaming it Aurelianum, or Aureliana Civitas, "city of Aurelian" (cité d'Aurélien), which evolved into Orléans.
In 442 Flavius Aetius, the Roman commander in Gaul, requested Goar, head of the Iranian tribe of Alans in the region to come to Orleans and control the rebellious natives and the Visigoths. Accompanying the Vandals, the Alans crossed the Loire in 408. One of their groups, under Goar, joined the Roman forces of Flavius Aetius to fight Attila when he invaded Gaul in 451, taking part in the Battle of Châlons under their king Sangiban. Goar established his capital in Orléans. His successors later took possession of the estates in the region between Orléans and Paris. Installed in Orléans and along the Loire, they were unruly (killing the town's senators when they felt they had been paid too slowly or too little) and resented by the local inhabitants. Many inhabitants around the present city have names bearing witness to the Alan presence – Allaines. Also many places in the region bear names of Alan origin
In the Merovingian era, the city was capital of the Kingdom of Orléans following Clovis I's division of the kingdom, then under the Capetians it became the capital of a county then duchy held in appanage by the house of Valois-Orléans. The Valois-Orléans family later acceded to the throne of France via Louis XII then Francis I. In 1108, one of the few consecrations of a French monarch to occur outside of Reims occurred at Orléans, when Louis VI of France was consecrated in Orléans cathedral by Daimbert, archbishop of Sens.
The climate here is mild, and generally warm and temperate. Precipitation in Orleans is significant, with precipitation even during the driest month. According to Köppen and Geiger climate is classified as Cfb. The average temperature in Orleans is 10.8 ° C. The approximate average rainfall is 641 mm.
Orléans is located in the northern bend of the Loire, which crosses from east to west. Orléans belongs to the vallée de la Loire sector between Sully-sur-Loire and Chalonnes-sur-Loire, which was in 2000 inscribed by UNESCO as a World Heritage Site. The capital of Orléanais, 120 kilomètres south-south-west of Paris, it is bordered to the north by the Beauce region and the forêt d'Orléans, and the Orléans-la-Source neighbourhood and the Sologne region to the south.
Conversely, the south (on the "rive gauche") has a gentle depression to about 95 m (312 ft) above sea level (at Saint-Marceau) between the Loire and the Loiret, designated a "zone inondable" (flood-risk zone).
At the end of the 1960s, the Orléans-la-Source quarter was created, 12 kilometres (7 mi)to the south of the original commune and separated from it by the Val d'Orléans and the Loiret River (whose source is in the Parc Floral de la Source). This quarter's altitude varies from about 100 to 110 m (330 to 360 ft).