Lothair, born near the end of 941, was the son of Louis IV and Gerberga of Saxony. He succeeded his father in 954 at the age of thirteen and was crowned at the Abbey of Saint-Remi by Artald of Reims, Archbishop of Reims. Lothair's mother made an arrangement with her brother-in-law Hugh the Great, Duke of the Franks and Count of Paris, who had been an adversary to Lothair's father. In exchange for supporting Lothair's rule Hugh was given rule over Aquitaine and much of Burgundy as more or less a Viceroy. Lothair inherited a kingdom where his great magnates took lands, rights and offices almost without any regard for the king's authority. Magnates like Hugh the Great and Herbert II, Count of Vermandois were always a veiled threat.
In 955, Lothair and Hugh together took Poitiers by siege. Hugh died soon after and Lothair mediated between his sons, the aforementioned Hugh Capet and the younger Otto Henry. The king gave Capet Paris and the ducal title, but invested Otto with the Duchy of Burgundy in 960. With young Hugh the new count of Paris et al., Lothair, now only fifteen, came under the guardianship of his maternal uncle Bruno, archbishop of Cologne (wikipedia.com)