Louis was crowned in June of 979 but did not actually assume power until Lothair's death in 986. Louis V was the last Carolingian king of France and reigned in Laon from March 2, 986 until his own death, at the age of 20, in 987. It may be because he reigned for only one year that medieval biographers awarded him the title qui nihil fecit — "who did nothing".
He married Adelaide of Anjou in 980 in Brioude, where they were immediately crowned King and Queen of Aquitaine. The couple was mismatched, as the age difference was great between the two, and they had no children together. She soon divorced him and fled his house in 982 to Arles.
He inherited a battle between his father's line of elected kings, which had been interrupted twice by the Robertian kings, and the house of the Holy Roman Emperor Otto I. As defender of Rome, Otto had the power to name the clergy in Carolingian territory, and the clergy he had named were not supporting the Carolingians.
One particular foe was Adalberon, archbishop of Reims whom Otto I had elevated to the powerful archbishopric of Reims. During Lothair's time, Adalberon had tried to negotiate an alliance between the two houses; but the deal had gone bad, and Lothair had tried him for treason in 986. Lothair died at around the same time. Louis V inherited the throne, Lothair's widow, Emma, married a descendant of Otto I, and Louis V received Adalberon again.
Louis died in late May of 987, either accidentally or of poisoning by his mother; at the time of his death, he was again trying Adalberon for treason. He left no legitimate heirs, so his uncle Charles, the Duke of Lower Lorraine, was advanced as the hereditary successor to the throne. But the clergy, including both Adalberon and Gerbert (who later became Pope Sylvester II), argued eloquently for Hugh Capet, who was not only of noble blood but had proven himself through his actions and his military might. Capet was elected to the Frankish throne and Adalberon crowned him, all within two months of Louis V's death. Thus the Carolingian dynasty ended and the Capetian began.