The Cossacks vigorously followed up the flying foe, and swept all before them, cutting and thrusting at the little knots who vainly offered resistance, fighting their way through blazing villages, and keeping the beaten Germans on the run. Try as they might, the Germans could not stay the torrent of the Russian advance. They tried to rally at Insterburg, their next line of defence, but all in vain, and were obliged to fall back for safety on the fortress of Königsberg. As they retreated a new peril appeared, and their flight became so rapid that they were obliged to abandon food, stores, ammunition, and guns. [Illustration: The Tsar and his Commander-in-Chief, the Grand Duke Nicholas. _Photo, Newspaper Illustrations, Ltd._] What was this new peril? While Rennenkampf was attacking the enemy, Samsonov's army had advanced northward with as much speed as the difficult nature of the ground would permit, and on 20th August his vanguard came upon the 20th German Corps strongly entrenched on a line about forty miles to the south-east of Königsberg. The Russians advanced as furiously and as doggedly as they had done at Gumbinnen, and, aided by their artillery, carried the German trenches with hand grenades[38] and the bayonet. About eleven next morning the German right was turned, and the left fled towards the south-west, while the remainder, hotly pursued by Cossacks, hurried towards Königsberg. When the news of this defeat reached the Germans who were retreating farther north, and they learnt that a new army was on their flank, they hastened with all speed towards Königsberg. These two victories made the Russians masters of East Prussia. They occupied Tilsit, on the Niemen--where, you will remember, Napoleon and Alexander of Russia met on a raft in the river to make plans for dividing Europe between them[39]--and marched on Königsberg. There was great joy in Russia when these victories were reported, and on the 27th of August a sum of £20,000 was raised by the sale of flags in Petrograd,[40] to be given to the first Russian soldier who entered Berlin. * * * * *