To secure his western border, Charles concluded a treaty with Louis XI of France and then prepared to march into the Rhine valley; contemporaries suspected his real motive was the eventual reconquest of all of Alsace.
Fearing the threat Neuss would pose to his exposed rear if left uninvested, Charles prepared to lay siege to the city, and the investment began on 29 July 1474.
Charles's army set up siege lines to the North and West of the city; the South and East were guarded by the rivers Krur and Rhine, respectively.
The next night, Kölners floated a fire-boat down the Rhine to destroy Charles' pontoon bridges, but the Burgundian river-fleet diverted it successfully.
The Neussers, bolstered by Hermann's Hessian troops and the support of Kölners, who skirmished with the Burgundians and smuggled provisions into the city while disguised as Italians, held out resolutely.
[3] In Ash: A Secret History by Mary Gentle, the Siege of Neuss has the title character's mercenary company involved in a skirmish with Charles the Bold's forces.