Operation Sea Lion (wargame)

The wargame was devised by Dr. Paddy Griffith, a historian at the Royal Military Academy Sandhurst, as part of a course on the Second World War. It aimed to rigorously test the historical plans for Operation Sea Lion, the proposed German amphibious invasion of Britain, using the knowledge of both Allied and Axis participants. The game was played on a large map of the English Channel and southeast England, with rules simulating naval, air, and land combat. Notably, the German side was commanded by former Wehrmacht officers, while the British side included veterans of the Royal Navy and Army, providing authentic tactical perspectives.

The game began with the German invasion fleet crossing the Channel, protected by the Luftwaffe and mines. The Royal Navy, though initially caught off guard, launched counterattacks with cruisers and destroyers. In the game, the Germans managed to land troops on the south coast, but the Royal Navy's relentless attacks on their supply lines and the lack of air superiority led to a grinding stalemate. The German forces, isolated and short of ammunition, were eventually forced to surrender after several days of simulated combat. The outcome was a decisive British victory, but the game highlighted that the Royal Navy would have suffered significant losses, including several destroyers sunk.

The wargame's findings reinforced the consensus that Operation Sea Lion was never a viable option for Germany. It demonstrated that the Kriegsmarine's lack of amphibious capability and the Royal Navy's numerical superiority would have doomed the invasion. However, the game also revealed that the British would have faced a serious threat if the Luftwaffe had achieved air superiority, as the Royal Navy's ships would have been vulnerable to air attack. The exercise has been cited in numerous historical works as a compelling simulation of the invasion's likely course, and it influenced later academic debates about the feasibility of the operation.

A lesser-known detail is that the wargame was not a single event but a series of exercises run over several years, with variations in rules and scenarios. One variant tested the impact of a delayed invasion, while another examined the role of the Home Guard. The game also inspired a 1978 book, 'Operation Sea Lion' by Peter Fleming, which drew on the exercise's findings. Additionally, the wargame's design influenced later military simulations, including those used by the British Army for training. The participation of German veterans, such as General Adolf Heusinger, added a layer of authenticity that is often overlooked in popular accounts.

Kriegsmarine

The German Navy during the Second World War.

Luftwaffe

The German Air Force during the Second World War.

Home Guard

A British defence organisation of part-time volunteers during the Second World War.