By the early 700s the Frankish kings of the Merovingian family reigned but no longer ruled. Real power belonged to their chief officials, the mayors of the palace. One of them, Charles Martel, made his name in battle: in 732 Charles Martel defeated an Umayyad army near Tours and Poitiers. Later writers turned this into the battle that saved Christian Europe; many historians now see it as the defeat of a large raid rather than a full invasion. Either way, it raised his family's prestige.
His son took the final step. Pepin the Short deposed the last Merovingian king in 751 with the pope's approval and was anointed king. The bargain bound the new Carolingian dynasty (from Carolus, Latin for Charles) to the papacy, which needed a protector against the Lombards in Italy.
Charlemagne
Pepin's son Charles, called Charlemagne (Charles the Great), ruled from 768 to 814. He spent most of those years at war. He conquered the Lombard kingdom in 774 and fought the pagan Saxons for about three decades, forcing baptism on them at sword point. The Royal Frankish Annals report that in 782 he had 4,500 Saxon prisoners executed at Verden; the number may be inflated, but the brutality was real. By 800 he ruled most of western Christendom outside Britain and Spain.
On Christmas Day 800, Pope Leo III crowned Charlemagne emperor in Rome. His biographer Einhard claimed Charlemagne would not have entered the church that day had he known what the pope planned. Historians debate whether this was modesty or irritation that the pope had cast himself as the maker of emperors. The coronation also offended the emperors at Constantinople, who saw themselves as the only Roman emperors. Einhard also reports that Charlemagne, who read and spoke Latin, tried late in life to learn to write, keeping tablets under his pillow, but started too late to master it.
Ruling a huge realm
Charlemagne had no Roman-style bureaucracy. He governed through hundreds of counts, through bishops and abbots, and through written instructions called capitularies. To keep the counts honest he sent out the missi dominici, pairs of royal envoys, usually a churchman and a layman, who inspected local government and heard complaints. The system depended heavily on his personal energy.
The Carolingian Renaissance
Charlemagne wanted educated clergy who could read the Bible and the liturgy correctly. He gathered scholars at his court in Aachen, led by the English monk Alcuin of York. Scribes of this era developed Carolingian minuscule, a clear script with lowercase letters and spaces between words. Renaissance printers later revived it, and the lowercase letters you are reading descend from it. Carolingian copyists also saved many classical Latin works that would otherwise be lost.
The empire did not survive his grandsons. After a civil war, the Treaty of Verdun in 843 divided the empire among Charlemagne's three grandsons. The western share grew into France, the eastern into Germany, and the strip between them was fought over for a thousand years.
The Northmen
As Carolingian unity broke down, raiders came from Scandinavia. The Viking attack on the island monastery of Lindisfarne in 793 is usually taken as the start of the Viking Age in the West. Monasteries made rich, undefended targets. Over the next century Viking fleets sailed up the Seine, sacked Paris in 845 and besieged it in 885, and settled large parts of England, Ireland and Scotland.
Raiding was only part of the story. Vikings were also farmers, traders and settlers. Swedes known as the Rus traded and ruled along the rivers of what is now Russia and Ukraine. Norse settlers reached Iceland and Greenland, and at L'Anse aux Meadows in Newfoundland they built a short-lived camp; a 2021 tree-ring study showed they cut wood there in the year 1021.
Rulers learned to fight back or to buy peace. Alfred of Wessex defeated the Danish leader Guthrum at Edington in 878, and England was divided between Alfred's kingdom and the Danelaw. Across the Channel, in 911 the Frankish king Charles the Simple granted the Viking leader Rollo the lands that became Normandy, on condition that he defend them against other raiders. Rollo's descendants, the Normans, would conquer England in 1066. To the east, the German king Otto I crushed the raiding Magyars at Lechfeld in 955 and was crowned emperor in 962.
Worked example: how Alcuin explained Lindisfarne
When news of the raid reached Alcuin at Charlemagne's court, he wrote to the king of Northumbria and to the monks. He said nothing like this terror had ever been seen in Britain, and that no one had thought such a voyage from the sea possible. Then he asked what sins had brought the punishment: luxury in dress, greed, injustice by the powerful.
Notice two things. First, Alcuin read a military event as a moral one, which was normal for a medieval churchman and tells us about his worldview. Second, almost all of our early evidence for Vikings comes from their victims, mostly monks, so it dwells on burning and looting. The Norse sagas that celebrate Viking voyages were written down in the 1200s, centuries later and for very different audiences. A fair picture has to weigh both kinds of bias and add archaeology, which reveals trading towns, silver hoards and farms.