Fall Rot, Case Red, was the second phase of the German offensive against France in 1940. The German High Command had planned for Fall Rot to proceed on the positive outcome of Fall Gelb. On June 4 the last evacuees were leaving Dunkirk, effectively ending Fall Gelb.
The French had lost significant numbers of men and material in the north and had a line of almost 1000 km to defend, they were, however, falling back on their reserves and supply lines and had managed to make good some of the losses; they had 65 divisions to the Germans 142 divisions. The new French commander, Weygand, made plans to establish fortified strong points called hedgehogs to slow the German advance down giving time to co-ordinate counter-offensives.
Fall Rot was initiated on June 5 with a strike by Army Group B over the Somme aimed at the Seine along the west coast followed on June 9 by a main strike south towards Paris and on. The German attacks faced a very determined enemy who had gained experience and learnt from their mistakes over the previous month. The Germans found the going tough but has the French were worn down they had no reserves to plug gaps. Consequently on June 10 a breakthrough was achieved near Abbeville and the French line started to collapse. The Luftwaffe played an important part in the attacks, concentrating on strong points and denying the French the opportunity to focus their troops.
Army Group A was tasked with outflanking and rolling up the Maginot line. Army Group C were to attack the Maginot Line frontally. On June 17 Guderian reached the Swiss border and completed the envelopment of the Maginot Line.
On June 10 the French declared Paris an open city. On June 14 it fell to the Germans. Churchill had attended a meeting on June 13 and proposed a union between Britain and France so that France could remain in the war but this was rejected by the French government. On June 16 French Prime Minister Paul Reynaud resigned to be replaced by Marshal Philippe Pétain, who immediately announced his intention to seek an armistice with the Germans.
On June 22 negotiations took place at Compiègne and the armistice was put into practice on June 25 effectively ending the Battle of France.
Timeline
Case Red - German Offensive south begins.
Paris is taken.
Armistice signed.
Ceasefire - Battle of France is over.