keyboard_arrow_right The first phase of the battle for the Atlantic lasted from the autumn of 1939 until the fall of France in June 1940. During that period the Anglo-French coalition drove German merchant shipping from the sea and established a fairly effective long-range blockade, while the German navy attempted to inflict some measure of damage on Allied forces at sea. The battle took a radically different turn in May–June 1940, following the Axis conquest of the Low Countries, the fall of France, and Italy’s entry into the war on the Axis side. Britain lost French naval support just when its own sea power had been hurt by losses incurred in the retreat from Norway and the evacuation from Dunkirk and stretched by Italian belligerency. Axis air power imperiled and eventually barred the direct route through the Mediterranean Sea to the Suez Canal, forcing British shipping to use the long alternative route around the Cape of Good Hope. That cut the total cargo-carrying capacity of the British merchant marine almost in half at the very moment when German acquisition of naval and air bases on the Atlantic coast foreshadowed more destructive attacks on shipping in northern waters.