The siege was the most important event of the reign of Charles the Fat, and a turning point in the fortunes of the Carolingian dynasty and the history of France.

It also proved for the Franks the strategic importance of Paris at a time when it also was one of the largest cities in West Francia.

The siege is the subject of an eyewitness account in the Latin poem Bella Parisiacae urbis of Abbo Cernuus.

With hundreds of ships, and possibly tens of thousands of men, the Vikings arrived outside Paris in late November 885, demanding tribute.

To the frustration of the Parisians who had fought to defend the city, Charles stopped short of attacking the Viking invaders.

Instead, he allowed them to sail farther up the Seine to raid Burgundy (which was in revolt) and promised a payment of 700 livres (257 kg) of silver.

Although the Vikings had attacked parts of Francia previously, they reached Paris for the first time in 845, eventually sacking the city.

[5][3] Vikings under Sigfred and Sinric[6] sailed towards West Francia again in 885, having raided the north-eastern parts of the country before.

Sigfred demanded a bribe from Charles, but was refused, and promptly led 700 ships up the Seine, carrying perhaps as many as 30,000[3] or 40,000 men.

[7] The number, the largest ever recorded for a Viking fleet in contemporary sources, originates from Abbo Cernuus.

[3] Odo, Count of Paris prepared for the arrival of the Vikings by fortifying the bridgehead with two towers guarding each bridge.

[17] The Vikings withdrew after the failed initial attacks and built a camp on the right side of the riverbank, using stone as construction material.

[19] In a renewed assault, they shot a thousand grenades [clarification needed] against the city, sent a ship for the bridge, and made a land attack with three groups.

[17] The Vikings left a force around Paris, but many ventured further to pillage Le Mans, Chartres,[17] Evreux and into the Loire.

[17] Weakened by marching during the winter, Henry's soldiers made only one abortive attack in February before retreating.

[17] When the Vikings withdrew from France the next spring, he gave them 700 livres (pounds) of silver as promised,[22][23] amounting to approximately 257 kg.

[24] The Parisians and Odo refused to let the Vikings down the Seine and the invaders had to drag their boats overland to the Marne to leave the country.

[22] Throughout the 9th century, the Robertians, descendants of Robert the Strong, held the crown and remained leading figures in West Francia.