In 1815 deposed emperor Napoleon returned to France and threatened the already devastated and exhausted continent with yet another war. Near the small Belgian municipality of Waterloo, two large, hastily mobilized armies faced each other to decide the future of Europe--Napoleon's forces on one side and the Duke of Wellington's on the other.

With so much at stake, neither commander could have predicted that the battle would be decided by the Second Light Battalion, King's German Legion, which was given the deceptively simple task of defending the Haye Sainte farmhouse, a crucial crossroads on the way to Brussels.

In The Longest Afternoon, Brendan Simms recounts how these 400-odd riflemen beat back wave after wave of French infantry until they were finally forced to withdraw but only after holding up Napoleon for so long that he lost the overall contest. Their actions alone decided the most influential battle in European history.