May-June 1940, Low Countries : A series of German victories sealed the fate of French, Dutch, Belgian, and British Expeditionary Force armies in western Europe. Entire campaign divided into four timelines : 1) Conquest Holland & Belgium, 2) Battles at Sedan and Arras, 3) Dunkirk Evacuation, 4) France Surrender. Allied strategic plan was to rely upon French Maginot Line fortifications at France-German border to forestall German offensive, thus allotting enough time to bring reinforcements to frontline critical points. France-Belgium border was unfortified since French and British viewed mass mechanized columns could not transverse Ardennes forest in timely manner at Germany-Belgium-Luxembourg border. Maginot Line - en.wikipedia.org/wiki/Maginot_line

Fall Gelb (Case Yellow) : first German plan for conquest of Low Countries, envisioned conventional linear assault upon various Allied strong points. German Chancellor Adolf Hitler, being a veteran and personally witnessed mass causalities suffered by his WW1 comrades in such frontal attacks, was not enthusiastic about its prospects. 9 Jan 1940, German military liaison plane crashed in Belgium divulging German plans to Allies, prompting its cancellation. Fall Sicklestroke : second German plan for Low Countries operations, envisioned non-conventional forces (ex. Fallschirmjager paratroopers & Waffen-SS sappers) in isolating Allied strong points until main German forces arrive, was put into effect. FYI, Low Countries traditionally referred to Holland, Belgium, and Luxembourg in geographically low-lying areas around Rhine, Scheldt, and Meuse rivers delta. Low Countries - en.wikipedia.org/wiki/Low_countries

10 - 14 May, 1940 : Germans amassed 136 divisions (of which 10 were fully constituted Panzer divisions), countered by Allies 137 divisions (94 French, 12 British, 22 Belgian, 9 Dutch) of out which French mustered 3 armored divisions and British only one. With superior tactics and coordination, German launched combined assaults by Fallschirmjagers and Panzer forces into Holland and Belgium, captured major strong points for advancing mechanized forces. Most spectacular was Fallschirmjager capture of Belgian fortress Eben Emael and bridge crossings over Albert Canal. Holland surrendered on May 14th. Fort Eben-Emael - www.fort-eben-emael.be

Rollover : 15 - 23 May 1940 : Germans outflanked French Maginot Line by transversing over 40 divisions in rapid succession through Ardennes Forest, fanning out into multi-prong drives across Belgian-French frontier driving for English Channel. May 14th, Germans successfully crossed last major natural obstacle of Meuse River at SEDAN within 24 hours (French thought it would take Germans 4 days to cross river in large numbers). May 20th - 23rd, Allies armored counter-attacks failed to severe German"Panzer Corridor" at ARRAS (only 75% of Allied armor had radios, hence fluid battle coordination was difficult at best). Results of which, bulk of Allied battle groups trapped in north, begun withdrawal to Dunkirk and Calais coastal cities. Belgium surrendered on May 28th. Ardennes - en.wikipedia.org/wiki/Ardennes

23 May - 5 June 1940 : Allied forces squeezed into costal perimeters, British government activated on May 23rd Operation Dynamo : mass naval evacuation of Dunkirk. Germans pushed within 2 miles of coast, placing entire region under artillery and aerial bombardment. RAF dispatched fighter protection over beach head, one sortie was flown by Pilot Officer Gray depicted in this Spitfire model. Operation Dynamo - http://en.wikipedia.org/wiki/Operation_Dynamo