The Franks (Latin: Franci) were a Western European people who began in the third century as a group of Germanic tribes near the Lower Rhine River, but gradually became a multilingual, Catholic Christian people, who controlled a large territory both inside and outside the former Roman Empire. Much of what is now the Netherlands, Germany, Belgium, Luxembourg, France, and in a broader sense much of the population of medieval Western Europe, could eventually be described as Frankish, depending on the context.
Pre-existing Germanic tribes such as the Bructeri and Chattuari began being referred to as Franks during the crisis of the 3rd century, when Rome lost control of regions near the lower Rhine, within the Roman province of Germania Inferior. The Rhine was a militarized border defended by the Romans, and the Frankish tribes had been living across the Rhine under Roman hegemony for centuries, under other tribal names. During the crisis they made frequent incursions, and in some cases settled areas on the Roman side. Despite the reassertion of Roman authority in the 4th century, Franks continued to live semi-independently on both sides of the Rhine, while the Romans came to agreements with them, recruiting large numbers of Frankish soldiers, some of whom achieved high imperial rank.
When the Roman administration of Britain and northern Gaul eventually broke down once more in the fifth century, it was the Franks who attempted to defend the Roman border in 406 when a largescale Rhine crossing was made by Alans and Vandals from eastern Europe. Frankish kings subsequently divided up Germania Inferior between them, and at least one, Chlodio, also began to rule more Romanized populations to the south, in what is now northern France. In 451, Frankish groups participated on both sides in the Battle of the Catalaunian Plains, where Attila and his allies were defeated by a Roman-led alliance of various peoples established in Gaul. By the early 6th century, the whole of Gaul north of the Loire, and all the Frankish kingdoms, were united within the kingdom of the Frank Clovis I, the founder of the Merovingian dynasty. By building upon the basis of this empire, the subsequent Frankish dynasty, the Carolingians, eventually came to be seen as the new emperors of Western Europe in 800, when Charlemagne was crowned by the pope.
As the original Frankish communities merged into others, the term Frank lost its original meaning. In 870, the Frankish realm was permanently divided between western and eastern kingdoms, which were the predecessors of the later Kingdom of France and Holy Roman Empire respectively. The Latin term Franci, and equivalents in other languages, came to refer mainly to the people of the Kingdom of France, the forerunner of present day France. However, in various historical contexts, such as during the medieval crusades, not only the French, but also people from neighbouring regions in Western Europe, continued to be referred to collectively as Franks. The crusades in particular had a lasting impact on the use of Frank-related names, which are now used generically for all Western Europeans in many non-European languages.
While the original meaning of the word is not certain, it is commonly believed to have a Germanic etymology. Following the precedents of Edward Gibbon and Jacob Grimm, the name of the Franks was traditionally linked to Old French franc, and related terms such as the English adjective frank, meaning "free". This term is however derived from the term Frank itself, as it referred to their free status. Similarly, the word has been connected to a Germanic word for "javelin", reflected in words such as Old English franca or Old Norse frakka, but these terms possibly also derive from the name of the Franks, as the name of a Frankish weapon. Alternatively, this Germanic word may share its origins with an older term recorded in Latin framea, which was used to describe the javelin used by Germani already in the first century.
A common proposal to explain the ultimate origin of all these terms is that it meant "fierce". According to one version of this proposal, the name is related to a proto-Germanic word which has been reconstructed, *frekaz, which meant "greedy", but sometimes tended towards meanings such as "bold". It has descendants such as German frech (cheeky, shameless), Middle Dutch vrec (miserly), Old English frǣc (greedy, bold), and Old Norse frekr (brazen, greedy).
The traditional idea that the name of the Franks meant fierce is partly derived from classical stereotypes of their ferocity and unreliability. For example, Eumenius rhetorically addressed the Franks when Frankish prisoners were executed at Trier by Constantine I in 306: Ubi nunc est illa ferocia? Ubi semper infida mobilitas? ("Where now is that ferocity of yours? Where is that ever untrustworthy fickleness?"). Isidore of Seville (died 636) said that there were two proposals known to him. Either the Franks took their name from a war leader who founded them, called Francus, or else their name referred to their wild manners (feritas morum).
The origins of the term Franci (singular Francus) are unclear, but by the 4th century it was commonly used as a collective term to refer to several tribes who were also known to the Romans by their own tribal names. It also became a more commonly used term than the older but much broader collective name Germani, which also covered many non-Frankish peoples such as the Alemanni and Marcomanni. Within a few centuries the term had eclipsed the names of the original peoples who constituted the Frankish population.
After their conquest of northern Gaul, many Germanic-speaking Franks lived in communities where the majority population was not Frankish, and the dominant language was Gallo-Roman. However, as the Franks became more powerful, and more integrated with the peoples they ruled over, the name came to be more broadly applied, especially in what is now northern France. Christopher Wickham pointed out that "the word 'Frankish' quickly ceased to have an exclusive ethnic connotation. North of the River Loire everyone seems to have been considered a Frank by the mid-7th century at the latest (except Bretons); Romani (Romans) were essentially the inhabitants of Aquitaine after that".
As societies changed, the name acquired new meanings, and the old Frankish community ceased to exist in its original form.
In Europe in later times, it was mainly the inhabitants of the Kingdom of France who came to be referred to in Latin as the Franci (Franks), although new terms soon became more common, which connect the French to the earlier Franks, but also distinguish them. The modern English word "French" comes from the Old English word for "Frankish", Frenċisċ. Modern European terms such as French français and German Franzose, derive from Medieval Latin francensis meaning "from Francia", the country of the Franks, which for medieval people was France. In Medieval Latin, French people were also commonly referred to as francigenae, similarly meaning "from Francia" or literally "Francia-born".
Similarly to France, the region of Franconia (German: Franken) in what is now Germany has a name which originally referred to the Franks, but developed a distinct meaning over time. It was an eastern extension of the core Frankish Merovingian empire. It became the medieval Duchy of Franconia in the Holy Roman Empire which evolved from the eastern part of the Frankish empire. Unlike France, despite the role that Franks played in creating this eastern realm most of it did not come to be considered Frankish. Franconia's name therefore contrasted it with the similarly powerful non-Frankish stem duchies east of the Rhine: Thuringia, Swabia, Saxony, and Bavaria.
In contrast to France and Franconia, the centrally-positioned Frankish lands west of the Rhine came to be referred to by other names. The region was initially the core of Merovingian Frankish Austrasia, which ruled over early Franconia east of the Rhine, and was contrasted to Frankish Neustria to its the west, in France. The part of Austrasia west of the Rhine later came to be referred to as Lotharingia, after its Carolingian Frankish king Lothair II. However, after his death the region was divided between the eastern and western Franks and never regained lasting independence.