The siege of Nieuport (4-18 July 1794) was one of the more controversial events during the Allied retreat from Belgium into the Netherlands after the French victory at Fleurus (26 June). Nieuport was held for the British by a garrison made up of 2,000 Hanoverians and around 500 French émigrés. As the Duke of York retreated out of Belgium, it was inevitable that Nieuport would be exposed to a French siege. On 2 July the Duke wrote to Henry Dundas, who then had authority over the conduct of the war, to ask what he should do with at Nieuport, and to warn him not to leave the émigrés exposed to capture. This letter crossed with one of Dundas of 3 July from Dundas to General Diepenbrock, the commander at Nieuport, in which he promised to help with any evacuation but made it clear that he wanted to hold the port if possible.
The French soon rendered the debate pointless. General Moreau sent a brigade under General Dominique Vandamme to attack the port. They arrived outside Nieuport on 4 July, and after a short siege of two weeks the garrison was forced to surrender. While the Hanoverians were taken prisoner, the émigrés were forced into the ditch outside the fort and executed. The French then moved east to besiege Sluys (L'Ecluse). The Duke of York was later blamed for the fate of the émigrés, although the decision to hold the port was actually made by Dundas.