Background
On 6 December 884, King Carloman II of West Francia died without a male heir and his half-brother, the future Charles the Simple, was just a five-year-old boy. Because of this, their cousin Charles the Fat, already Holy Roman Emperor and King of East Francia, was invited by the nobles of the Kingdom to assume the throne. Since the beginning, the new monarch was forced to deal with constant Viking raids, with little success. After three years of incompetent government, Charles the Fat was finally deposed by the Diet of Tribur in 887.
Faced with the growing threat of northern invaders, the local nobles again rejected the succession of Charles the Simple because he was too young, and Odo, Count of Paris (member of the Robertian dynasty) was chosen as the new King of West Francia, after successfully defending Paris against the Vikings, led by Rollo. In 893, aided by Archbishop Fulk of Reims, Charles the Simple attempted to reclaim the throne, but in vain. By 897, the young prince ruled only the city of Laon before Odo on his deathbed designated him as his successor.
Following the death of Odo in January 898, Charles the Simple finally assumed the title of king of West Francia. Soon the new monarch showed his ambition to conquer Lotharingia, the main objective of all the monarchs of West Francia since Charles the Bald. Lotharingia was the cradle of the Carolingian dynasty. Charlemagne's ancestors, the Pippinids were from Lotharingia (Herstal, Jupille...). After the Treaty of Verdun in 843, the Lotharingia was part of Middle Francia for a short time and both West and East Francia tried to gain control over it. Arnulf of Carinthia, King of East Francia prevented this by entrusting the land to his son Zwentibold in 895. Zwentibold was hated by his subjects, so Charles the Simple decided to invade in 898 after being called by Count Reginar of Hainaut. After seizing Aachen and capturing Charlemagne's Palace at Nijmegen, he returned to France at the request of the German bishops. A few years later, in September 911, the Lotharingian aristocracy again called on Charles the Simple after the death of Louis the Child, the last Carolingian ruler in East Francia.
Charles the Simple was crowned King of Lotharingia in early November 911. However, the constant absences of the new monarch (who preferred to stay in Aachen or Thionville), quickly irritated the Lotharingian nobility (who feared for their own independence) and nobles of France, who saw this inclination as an affront. The situation was even more complicated because, according to Flodoard, Charles the Simple refused to march against the Hungarians who threatened Lotharingia (only Archbishop Hervé de Reims was present there) and finally caused an open rebellion when he attempted to dispossess his own aunt, Abbess Rothilde (also mother-in-law of Hugh the Great), from Chelles Abbey in order to give it to his favourite, Hagano (a relative of his first wife Frederuna).
