Old French
Old French was the Romance
Romance languages
The Romance languages are a branch of the Indo-European language family, more precisely of the Italic languages subfamily, comprising all the languages that descend from Vulgar Latin, the language of ancient Rome...

 dialect continuum
Dialect continuum
A dialect continuum, or dialect area, was defined by Leonard Bloomfield as a range of dialects spoken across some geographical area that differ only slightly between neighboring areas, but as one travels in any direction, these differences accumulate such that speakers from opposite ends of the...

 spoken in territories that span roughly the northern half of modern France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 and parts of modern Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

 and Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

 from the 9th century to the 14th century. It was then known as the langue d'oïl
Langues d'oïl
The langues d'oïl or langues d'oui , in English the Oïl or Oui languages, are a dialect continuum that includes standard French and its closest autochthonous relatives spoken today in the northern half of France, southern Belgium, and the Channel Islands...

 (oïl language) to distinguish it from the langue d'oc (Occitan language, also then called Provençal), whose territory bordered that of Old French to the south.