The Zeebrugge Raid was an assault on the Imperial German Navy-held Belgian port of Zeebrugge by the Royal Navy and Royal Marine Forces on 23 April, 1918 (St. George's Day). The objectives of the raid, codenamed Operation ZO, were to block the approaches to the Zeebrugge-Bruges Ship Canal, and thus prevent the entry and egress of German submarines and destroyers from Bruges. The operation was only partially successful, as the blockships were poorly sited under heavy fire and blocked the canal for only a brief period of time. Casualties among the British force were considerable, with over two hundred killed and over three hundred wounded, while German casualties were reported to be insignificant. Bruges was still connected to the North Sea by a canal to Ostend, which the Royal Navy attempted to block twice, both times unsuccessfully.
The operation was planned by the Flag Officer Commanding the Dover Patrol, Acting Vice-Admiral Roger Keyes, and despite having not actually taken part in the fighting the raid made his name. Although the raid caused little actual damage, the Germans were compelled to concentrate more resources along the Belgian coast to prevent a re-occurrence of the raid. More importantly, the raid came as a great boost to the British people as the Germans continued to make gains in France after their Spring Offensives. Eight Victoria Crosses, the highest British and Empire award for gallantry in the face of the enemy, were awarded for action at Zeebrugge, second only to the eleven Victoria Crosses awarded at Rorke's Drift.
- Karau, Mark D. (2003). "Wielding the Dagger": The MarineKorps Flandern and the German War Effort, 1914-1918. Westport, CT: Praeger Publishers. ISBN 0-313-32475-1.
- Kendall, Paul (2009). The Zeebrugge Raid 1918: 'The Finest feat of Arms'. Brimscombe Port: Spellmount. ISBN 976-0-7524-5332-3.