The former Roman province of Gaul is the heartland of present-day France, ruled in the aftermath of the fall of Rome by the Franks, a powerful Germanic people who invaded Gaul from across the Rhine as Roman power crumbled. The Franks were a warlike and crafty group led by a clan known as the Merovingians. A Merovingian king, Clovis (r. 481 – 511) was the first to unite the Franks and begin the process of creating a lasting kingdom named after them: France. Clovis murdered both the heads of other clans who threatened him as well as his own family members who might take over command of the Merovingians. He then expanded his territories and defeated the last remnants of Roman power in Gaul by the end of the fifth century.
In 500 CE Clovis and a few thousand of his most elite warriors converted to Latin Christianity, less out of a heartfelt sense of piety than for practical reasons: he planned to attack the Visigoths of Spain, Arian Christians who ruled over Latin Christian former Romans. By converting to Latin Christianity, Clovis ensured that the subjects of the Goths were likely to welcome him as a liberator rather than a foreign invader. He was proved right, and by 507 the Franks controlled almost all of Gaul, including formerly-Gothic territories along the border.
The Merovingians held on to power for two hundred years. In the end, they became relatively weak and ineffectual, with another clan, the Carolingians, running most of their political affairs. It was a Carolingian, Charles Martel, who defeated the invading Arab armies at the Battle of Tours (also referred to as the Battle of Poitiers) in 732. Soon afterwards, Charles Martel’s son Pepin seized power from the Merovingians in a coup, one later ratified by the pope in Rome, ensuring the legitimacy of the shift and establishing the Carolingians as the rightful rulers of the Frankish kingdom.
Only the first few kings in the Merovingian dynasty of the Franks were particularly smart or capable. When Pepin seized control in 750 CE, he was merely assuming the legal status that his clan had already controlled behind the scenes for years. The problem facing the Franks was that Frankish tradition stipulated that lands were to be divided between sons after the death of the father. Thus, with every generation, a family's holdings could be split into separate, smaller pieces. Over time, this could reduce a large and powerful territory into a large number of small, weak ones. When Pepin died in 768, his sons Charlemagne and Carloman each inherited half of the kingdom. When Carloman died a few years later, however, Charlemagne ignored the right of Carloman’s sons to inherit his land and seized it all (his nephews were subsequently murdered).
Charlemagne (r. 768 – 814) was one of the most important kings in medieval European history. Charlemagne waged constant wars during his long reign (lasting over 40 years) in the name of converting non-Christian Germans to his east and, equally, in the name of seizing loot for his followers. From his conquests arose the concept of the Holy Roman Empire, a huge state that was nominally controlled by a single powerful emperor directly tied to the pope's authority in Rome. In truth, only under Charlemagne was the Empire a truly united state, but the concept (with various emperors exercising at least some degree of authority) survived until 1806 when it was finally permanently dismantled by Napoleon. Thus, like the western Roman Empire that it succeeded, the Holy Roman Empire lasted almost exactly 1,000 years.
Charlemagne distinguished himself not just by the extent of the territories that he conquered, but by his insistence that he rule those territories as the new, rightful king. In 773, at the request of the pope, Charlemagne invaded the northern Italian kingdom of the Lombards, the Germanic tribe that had expelled Byzantine forces earlier. When Charlemagne conquered them a year later, he declared himself king of the Lombards, rather than forcing a new Lombard ruler to become a vassal and pay tribute. This was an unprecedented development: it was untraditional for a Germanic ruler to proclaim himself king of a different people - how could Charlemagne be "king of the Lombards,” since the Lombards were a separate clan and kingdom? This bold move on Charlemagne’s part established the answer as well as an important precedent (inspired by Pepin’s takeover): a kingship could pass to a different clan or even kingdom itself depending on the political circumstances. Charlemagne was up to something entirely new, intending to create an empire of various different Germanic groups, with himself (and by extension, the Franks) ruling over all of them.
In 800, Charlemagne was crowned Holy Roman Emperor by the pope, Leo III. While Charlemagne’s biographers claimed that this came as a surprise to Charlemagne, it was anything but; Charlemagne completely dominated Leo and looked to use the prestige of the imperial title to cement his hold on power. Charlemagne had already restored Leo to his throne after Leo was run out of Rome by powerful Roman families who detested him. While visiting Italy (which was now part of his empire), Charlemagne was crowned and declared to be the emperor of Rome, a title that no one had held since the the western empire fell in 476. Making the situation all the stranger was the fact that the Byzantine emperors considered themselves to be fully “Roman” - from their perspective, Leo’s crowning of Charlemagne was a straightforward usurpation.
Charlemagne’s empire was a poor reflection of ancient Rome. He had almost no bureaucracy, no standing army, not even an official currency. He spent almost all of his reign traveling around his empire with his armies, both leading wars and issuing decrees. He did insist, eventually, that these decrees be written down, and the form of “code” used to ensure their authenticity was simply that they were written in grammatically correct Latin, something that almost no one outside of Charlemagne’s court (and some members of the Church scattered across Europe) could accomplish thanks to the abysmal state of education and literacy at the time.
Charlemagne organized his empire into counties, ruled by (appropriately enough) counts, usually his military followers but sometimes commoners, all of whom were sent to rule lands they did not have any personal ties to. He protected his borders with marches, lands ruled by margraves who were military leaders ordered to defend the empire from foreign invasion. He established a group of officials who traveled across the empire inspecting the counties and marches to ensure loyalty to the crown. Despite all of his efforts, rebellions against his rule were frequent and Charlemagne was forced to war against former subjects to re-establish control on several occasions.
Charlemagne also reorganized the Church by insisting on a strict hierarchy of archbishops to supervise bishops who, in turn, supervised priests. Likewise, under Charlemagne there was a revival of interest in ancient writings and in proper Latin. He gathered scholars from all of Europe, including areas like England beyond his political control, and sponsored the education of priests and the creation of libraries. He had flawed versions of the Vulgate (the Latin Bible) corrected and he revived disciplines of classical learning that had fallen into disuse (including rhetoric, logic, and astronomy). His efforts to reform Church training and education are referred to by historians as the "Carolingian Renaissance."
One innovation of note that arose during the Carolingian Renaissance is that Charlemagne instituted a major reform of handwriting, returning to the Roman practice of large, clear letters separated from one another and sentences that used spaces and punctuation, rather than the cursive scrawl of the Merovingian period. This new handwriting introduced the division between upper and lower-case letters and the practice of starting sentences with the former that we use to this day.
Ultimately, the Carolingian dynasty lasted for an even shorter period than had the Merovingian. The problem, again, was the Frankish succession law. Without an effective bureaucracy or law code, there was little cohesion to the kingdom, and areas began to split off almost immediately after Charlemagne’s death in 814. The origin of “Germany” (not politically united until 1871, over a thousand years after Charlemagne’s lifetime) was East Francia, the kingdom that Charlemagne’s son Louis the Pious left to one of his sons. A different line, not directly descended from the Carolingians, eventually ended up in power in East Francia. Its king, Otto I, was crowned emperor in 962 by the Pope, thereby cementing the idea of the Holy Roman Empire even after Charlemagne’s bloodline no longer ruled it.