Septimania is a historical region in modern-day southern France. It referred to the western part of the Roman province of Gallia Narbonensis that passed to the control of the Visigoths in 462, when Septimania was ceded to their king, Theodoric II. During the Early Middle Ages, the region was variously known as Gallia Narbonensis, Gallia, or Narbonensis. The territory of Septimania roughly corresponds with the modern French former administrative region of Languedoc-Roussillon that merged into the new administrative region of Occitanie. In the Visigothic Kingdom, which became centred on Toledo by the end of the reign of Leovigild, Septimania was both an administrative province of the central royal government and an ecclesiastical province whose metropolitan was the Archbishop of Narbonne. Originally, the Goths may have maintained their hold on the Albigeois, but if so it was conquered by the time of Chilperic I. There is archaeological evidence that some enclaves of Visigothic population remained in Frankish Gaul, near the Septimanian border, after 507.
The region of Septimania was invaded by the Andalusian Muslims in 719, renamed as Arbƫnah and turned into a military base for future operations by the Andalusian military commanders. It passed briefly to the Emirate of Córdoba, which had been expanding from the south during the same century, before its subsequent conquest by the Christian Franks in 759, who by the end of the 9th century renamed it as Gothia or the Gothic March (Marca Gothica). Eventually, the Christian Franks chased the Muslim Arabs and Berbers away from Septimania and conquered Narbonne in 759, and the Carolingian king Pepin the Short came up reinforced. Septimania became a march of the Carolingian Empire and then West Francia down to the 13th century, though it was culturally and politically autonomous from the northern France-based central royal government. The region was under the influence of the people from the count territories of Toulouse, Provence, and ancient County of Barcelona. It was part of the wider cultural and linguistic region comprising the southern third of France known as Occitania. This area was finally brought under effective control of the French kings in the early 13th century as a result of the Albigensian Crusade, after which it was assigned governors. From the end of the thirteenth century Septimania evolved into the royal province of Languedoc.