Hugh Capet founded a dynasty that ruled France, on and off, until 1848
In 987 Hugh Capet was elected king of the Franks in place of the Carolingians, succeeding Louis V. He reigned only nine years, but the House of Capet he founded held the throne through its senior line until 1328 and through cadet branches, with interruptions, all the way to 1848.
Hugh was born around 941, though no source records the date. His father was Hugh the Great, Duke of the Franks, and his mother Hedwige of Saxony was a daughter of Henry the Fowler, king of Germany. That made him a nephew of Otto the Great, while through his paternal grandmother Beatrice of Vermandois he descended from Charlemagne. His Robertian relatives had already twice been chosen king ahead of Carolingians, Odo in 888 and Robert I in 922, as nobles began to argue that the crown was elective.
The realm he would rule looked nothing like modern France. Kings styled themselves rex Francorum, king of the Franks, a title used until 1190, and controlled only a small slice of the old Carolingian empire; Normandy and Burgundy were largely autonomous and Brittany fully so. When his father died in 956, the teenage Hugh inherited vast estates, but former vassals such as Theobald of Blois and Fulk II of Anjou helped themselves to his lands while his mother acted as guardian.
His standing revived in 978. King Lothair, backed by Hugh, raided Aachen and forced Emperor Otto II's family to flee. Otto hit back by invading and besieging Paris, but winter sickness and a relief army under Hugh made him withdraw on 30 November, and his rearguard was lost trying to cross the flooded Aisne. The victory restored Hugh as the kingdom's leading noble.
The decisive backing came from the church. Archbishop Adalberon of Reims and his brilliant schoolmaster Gerbert of Aurillac, the future Pope Sylvester II, wanted a king who was neither Carolingian nor strong enough to defy Ottonian influence, and Hugh's support for monastic reform appealed to Reims. Gerbert quipped that Lothair was king in name only while Hugh ruled in deed. In 979 Hugh even presided over the anointing of Lothair's son Louis V at Compiègne; Louis would prove the last Carolingian king.
Source: Hugh Capet