War came in earnest for the Allies in May 1940, when Hitler invaded France, striking hardest where least expected. General Maurice Gamelin, the 68-Year old French commander in chief, was a picture of satisfaction on May 10, 1940. He had just received a note from Prime Minister Paul Reynaud, a long-standing opponent of appeasement who had succeeded Daladier as premier in March that year calling an end to a month’s long feud. Reynaud had written: “Mon general, the battle is engaged; only one thing matters; to win it.' The Germans had at last attacked, and from exactly the direction Gamelin had predicted through southern Holland and across the Flanders plain. At 7 am Gamelin activated the French masterstroke. By midday, giant 27 ton Char B tanks of France's First Army Group, led by, General Billotte, were crossing the Belgian frontier. Alongside the French moved the nine divisions of General Lord Gort's British Expeditionary Force (BEF), equipped with Matilda tanks, at that time the most heavily armoured tanks in the world. The Anglo-French armies advanced north through villages and towns filled with cheering Belgian civilians. Overhead circled squadrons of British and French fighters. Neither the French nor the British had ever moved such large armoured forces at one time before. Some units had spent the eight months of the so-called 'Phoney War' in static positions along the French-Belgian border. When the order to move came, at least 40 per cent of British vehicles and even more French ones broke down, and large traffic jams developed. Nonetheless, the British entered Brussels that evening, while other units began to deploy along the River Dyle to the east to await the German thrust. Advance and retreat: British troops with a Bren carrier take a roadside break in May 1940. Streaming in the opposite direction are Belgian refugees, fleeing the Germans. Gamelin was yet to realise it, but he had just advanced his most powerful formations into the greatest military trap ever devised. The German plan, nicknamed “Sichelschnitt” ('Sicklecut'), was audacious to the point of recklessness, the sort of scheme that a half crazed corporal, used to gambling on long odds and winning, might come up with. Such a man was Adolf Hitler. His erratic flair coupled with the professional attention to detail of one of his staff officers, Erich von Manstein, shaped the plan in its final form. Churchill Becomes Prime Minister On May 7, 1940, the House of Commons debated the Norway campaign. Prime Minister Chamberlain was already ill with the still undiagnosed cancer which would kill him six months later, and did not perform well. The 77-year-old Lloyd George, in his last great speech, spoke against him; Churchill's friend, Leo Amery, used Cromwell's words when he dismissed the Long Parliament in 1653: 'Depart, I say, and let us have done with you. In the name of God go!' When the House divided Chamberlain had won, but more than 30 Conservatives had supported the Opposition. On May 9 Chamberlain offered the Labour leaders, Attlee and Greenwood, places in a coalition government, but they would not serve under him. Determined that the alternative should not be Churchill, Chamberlain chose the foreign secretary, Lord Halifax. He summoned Churchill and Halifax to Downing Street, pointed out that Halifax was the king's choice and asked Churchill if he would serve under him. Churchill was silent. The seconds dragged by until Halifax, a shy man, could stand it no longer. He stammered out that he was willing to serve under Churchill. It was not the result Chamberlain or the king had wanted. But so it was that Churchill became premier on May 10, 1940. Top Brass: In January 1940 Churchill, still only First Lord of the Admiralty, stands with (from left to right) Generals Ironside, Georges, Gamelin and Gort.