The Maginot Line was a marvel of 1930s engineering. The huge forts, up to eighty meters underground, contained hospitals, modern kitchens, telephone exchanges, and even electric trains. Kilometres of underground galleries led to casements hidden in the terrain, and turrets that rose from the ground to fire upon the enemy. The fortifications were invulnerable to the heaviest artillery and to chemical warfare.

Despite this extensive preparation, France fell to Germany in a little under six weeks. Eight decades on, the Maginot Line is still remembered as an expensively misguided response to obvious danger.

In this groundbreaking account, Kevin Passmore reevaluates the Maginot Line. He traces the controversies surrounding construction, the lives of the men who manned the forts, the impact on German-speaking inhabitants of the frontier, and the fight against espionage from within. Far from a backward step, the Maginot Line was an ambitious project of modernisation--one that was let down by strategic error and growing dissatisfaction with fortification.