Then the Great Slav came to the rescue of the smaller. Russia immediately notified Austria that she would not allow Serbian territory to be invaded. Now it was Germany's turn. She let it be known semi-officially that she stood ready to back Austria. No one, she said, must interfere between Austria-Hungary and Serbia. On this twenty-seventh of July Sir Edward Gray, Great Britain's Foreign Secretary, proposed a London conference of the Ambassadors of all the Great Powers. France and Italy at once accepted but Austria and Germany declined this invitation. On the twenty-eighth of July came the fateful call to war. "Austria-Hungary considers itself in a state of war with Serbia." The reason given for this was that Serbia had not replied satisfactorily to Austria's note of the twenty-third of July. Events followed in quick succession. Russia's mobilization was followed by a request from Germany that she stop this movement of the troops and make a reply within twenty-four hours. Whereupon England notified Germany that she could not stand aloof from a general conflict; that the balance of power could not be destroyed. Russia made no reply to Germany's ultimatum but instead sent out a manifesto: "Russia is determined not to allow Serbia to be crushed and will fulfil its duty in regard to that small kingdom." Next, the German Ambassador at the French foreign office expressed fear of friction between the Triple Alliance and the Triple Entente unless the impending conflict between Austria and Serbia should be strictly localized. On August first, the German Ambassador handed a declaration of war to the Russian Foreign Minister. This meant war with France, and hardly had the French Government issued general mobilization orders when the invasion of France began. A day later, Germany demanded of Belgium free passage for her troops, and the French Government proclaimed martial law in France and Algiers. All Continental Europe was now aflame. The German Ambassador had made a strong bid for British neutrality, and Great Britain's reply was noble. After speaking of its friendship with France it concluded with the words: "Whether that friendship involves obligations, let every man look into his own heart and construe that obligation for himself."