East Francia
The history of Germany between 844 AD and 918 AD
In medieval historiography, East Francia or the Kingdom of the East Franks forms the earliest stage of the Kingdom of Germany, lasting from about 840 until about 962. East Francia was formed out of the division of the Carolingian Empire after the death of Emperor Louis the Pious.
In August 843, after three years of civil war following the death of Louis the Pious, the Treaty of Verdun was signed by his three sons and heirs. His namesake, Louis the German, received the eastern portion of mostly Germanic-speaking lands. The kingdom of West Francia went to Louis's younger half-brother Charles the Bald and between their realms a kingdom of Middle Francia, incorporating Italy, was given to their elder brother, the Emperor Lothair I. While West and Middle Francia contained the traditional Frankish 'heartlands', the East consisted mostly of lands only annexed to the Frankish empire in the eighth century. These included the duchies of Alemannia, Bavaria, Saxony and Thuringia, as well as the northern and eastern marches with the Danes and Slavs.
The external threat from marauding Vikings in the west and from Magyars in the east aggravates an already grave internal problem for the feudal dynasties of Charlemagne's descendants. Feudalism, with its decentralization of military and territorial power, has at the best of times a tendency to foster regional independence. In periods of crisis, when the regions need to be well armed if they are to repel invaders, it is almost inevitable that the feudal holders of large tracts of frontier territory grow in strength until they are capable of challenging their own king. Baronial contenders upset the succession to the throne in the west Frankish kingdom from the late 9th century and in the eastern kingdom a few years later.
In 911 the east Frankish king Louis the Child died without a male heir. The only legitimate claimant within the Carolingian dynasty is Charles III, ruler of the west Frankish kingdom. Rather than do homage to him, and reunite the empire of Charlemagne, the eastern Franks and the Saxons elected one of their own number to the vacant throne. Conrad, the duke of Franconia, became the German king. Although not of the Carolingian line, Conrad is nevertheless a Frank. But on his death the Franks and the Saxons together elect a Saxon king. In 919 Henry I becomes the founder of the Saxon, or Ottonian, dynasty.
References: Wikipedia