Did the Vikings ever conquer Paris?

Yes, Vikings started sailing West European rivers upstream around 800, and raided Paris several times in the 9th century. The whole Northern part of France was under constant attacks at the time, including Paris. read more

The Vikings attacked with a variety of siege engines, but failed to break through the city walls after some days of intense attacks. The siege was upheld after the initial attacks, but without any significant offence for months after the attack. As the siege went on, most of the Vikings left Paris to pillage further upriver. read more

Vikings returned again and again in the 860s and secured loot or ransom, but, in a turning point for the history of France, the city's walls held against the Vikings' greatest attacking force in the Siege of Paris (885–86). read more