The Frankish Empire under realm of the Carolingian Dynasty commonly referred as the Carolingian Empire reached its height during the reign of Charlemagne (768-814) who incorporated much of Western and Central Europe into the Carolingian Empire. Charlemagne started his military campaigns with the war against the Lombards who recaptured the Lombard cities which were granted to the Papacy by the Donation of Pepin. The request of Pope Hadrian I to provide military assistance against the Lombards was the immediate cause for Charlemagne’s campaign in Italy but the Frankish King was also disturbed by support of the Lombard king Desiderius to Charlemagne’s sister-in-law in her attempt to regain her children’s right to inheritance. The Frankish forces invaded Italy by crossing the Alps in 773, defeated the Lombards and conquered their capital Pavia in 774. Desiderius was deposed and banished to a monastery. Charlemagne proclaimed himself King of the Lombards, while the entire territory of the Lombard Kingdom except for Spoleto and Benevento was incorporated into Carolingian Empire.
Charlemagne started a war against the Saxons in 772, one year earlier than launching his campaign against the Lombards. However, the so-called Saxon Wars which resulted in expansion of the Frankish border almost to the Rhine River lasted for three decades. Meanwhile Charlemagne also led several military campaigns against the Moors in Spain (778-811) and established the Spanish March between the Pyrenees and the Ebro River. Charlemagne subdued Benevento in Southern Italy in 787, Bavaria in 788, destroyed the Avar state between 791 and 803 and led a series of campaigns against the Slavs. He created an empire extending from the Atlantic Ocean on the west, to Danube on the east and from Rhine on the north to Mediterranean Sea on the south before he was crowned emperor on Christmas day in year 800.
Charlemagne was succeeded by Louis the Pious (814-840). The latter divided the Carolingian Empire among his three sons Lothair, Louis the German and Pepin in 817 when the largest partition went to Lothair. The division caused jealousy among the brothers, while redivision after the birth of Charles the Bald from Louis’ second marriage further strained the relationships between his sons. On Louis’ death in 840 broke out a war between the three brothers (Pepin died earlier) Lothair, Louis the German and Charles the Bald which ended with the Treaty of Verdun in 843 and the division of the Carolingian Empire into:
- the Middle Francia or the central part of the empire (Low Countries, Lorraine, Alsace, Burgundy, Provence and Italy) was granted to Lothair I
- the East Francia (today’s Germany) went to to Louis the German
- the West Francia (today’s France) was gained by Charles the Bald
The Carolingian Empire continued to decline despite the agreement between the Louis’ successors. Charles the Bald had difficulties with constant uprisings in Aquitaine and with the invasions of the Vikings, Middle Francia lacked ethnic and linguistic unity, while East Francia which was economically the weakest part of the former Carolingian Empire was threatened by the Vikings and the Slavs from Moravia.
The Carolingian Empire was severely weakened by the principle of territorial division among the heirs which continued in all three kingdoms. All three sons of Lothair I died without a legitimate male heirs. Thus Italy and the territory between the Alps and North Sea known as Lotharingia were divided between their uncles Charles the Bald and Louis the German. The Carolingian Empire was once again united during the reign of Charles the Fat. He assured himself the imperial title and was elected King of all Franks on the death of Carloman II, the last adult Carolingian of the western branch in 884.
The unification of the Carolingian Empire lasted only until 887 when Charles the Fat was deposed. The illegitimate son of his brother Carloman, Arnulf of Carinthia was elected King of the East Franks, while non-Carolingian kings were elected in West Francia, Upper and Lower Burgundy, and Italy. Arnulf managed to retain a kind of supreme authority over kings of West Francia and Burgundy, gained Italy and the imperial title but his success was short lasting. Arnulf’s heir Louis the Child (900-911) was minor on his death and lost even the formal supremacy over West Francia where was elected Charles the Simple. The eastern frontiers were at the time severely endangered by the Hungarians who invaded and plundered Saxony, Franconia, Swabia, Lotharingia, Bavaria and Italy. Failure of the kings of the East Franks against the invaders in 9th and 10th centuries resulted in division of East Francia into stem duchies: Swabia, Bavaria, Saxony and Franconia.
Louis the Child died in 911 without a male heir. The Saxons and Franconians elected Duke of Franconia, Conrad I who was later also accepted by the Bavarians and Swabians. Election of Conrad I (911-918) finally ended the Carolingian rule in East Francia which is referred as the Medieval German state from the coronation of Henry I the Fowler in 919 onwards. The West Francia was ruled by the Carolingian Dynasty intermittently until 987 when Hugh Capet established the Capetian dynasty, while the kingdom came to be known as France.