him into an agreement. Charlemagne replaced him with Count William in 790. Charlemagne's reign saw the recovery of western Europe from the preceding dark age. Toulouse was a major Carolingian military stronghold against Muslim Spain, with military campaigns launched from the city nearly every year of Charlemagne's reign. In 801, Barcelona and a large part of Catalonia were conquered. With the northern areas of Aragon and Navarre in the Pyrenees, the region became the southern (Spanish March) of the Frankish empire. In 814, Charlemagne died. His only surviving son was Louis, king of Aquitaine, who became Emperor Louis the Pious. The kingdom of Aquitaine was transferred to Pippin, Louis' second son. Gothia was detached from Aquitaine and administered directly by the emperor, recreating the former duchy of Aquitaine. Louis had three sons, and in 817 he arranged an allocation of shares in their future inheritance. Pippin was confirmed king of Aquitaine, Louis the German was made king in Bavaria and eldest son Lothar became co-emperor (with future authority over his brothers). In 823 Charles the Bald, Louis the Pious' son with his second wife, was born and she wished to place her son in the line of succession. Strife between his three older sons and Louis and his new wife led to the gradual collapse of the Frankish empire. In 838 Pippin I of Aquitaine died, and Louis the Pious and his wife installed Charles the Bald as king of Aquitaine. At the 839 Assembly of Worms, the empire was re-divided. Charles the Bald received the western part of the empire, Lothar the central and eastern part and Louis the German Bavaria. Pippin II of Aquitaine, son of Pippin I who was recognized as king by the Aquitanians (but not the Basques, whose Vasconia had seceded from Aquitaine), and Louis the German opposed the partitions. Louis the Pious died in 840, Lothar claimed the empire and war broke out. Originally allied with his nephew Pippin II, Louis the German allied with his half-brother Charles the Bald and they defeated Lothar. In August 843, they signed the Treaty of Verdun. The empire was divided into three parts. Charles the Bald received the western part, Francia Occidentalis (Western Frankland, soon called France); Louis the German the eastern part, Francia Orientalis (Eastern Frankland, soon the German Holy Roman Empire), and Lothar received the central part (soon to be conquered and divided between his