The period was also marked by endless Viking raids on the kingdom and clashes between the West Franks and the Norsemen. The power vacuum left by a weak royal authority meant wars between fiefs were rampant, and so were conflicts between the vassals and the Frankish monarchs themselves. This was contrasted by the evergrowing power of their vassals over their large and usually territorially contiguous fiefs. In addition, by the 10th century the authority of the West Frankish monarchs was greatly reduced. It did not include such future French holdings as Lorraine, the County and Kingdom of Burgundy (the duchy was already a part of West Francia), Alsace and Provence in the east and southeast for example. West Francia extended further north and south than modern France, but it did not extend as far east. West Francia emerged from the partition of the Carolingian Empire in 843 under the Treaty of Verdun following the death of Charlemagne's son, Louis the Pious.
It represents the earliest stage of the Kingdom of France, lasting from about 840 until 987. In medieval history, West Francia ( Medieval Latin: Francia occidentalis) or the Kingdom of the West Franks ( regnum Francorum occidentalium) refers to the western part of the Frankish Empire established by Charlemagne.
