"When Barbarossa is launched, declared Hitler, the whole world will hold its breath!", and indeed the forces massed along the Soviet frontier from the Arctic Circle to the Black Sea during that early summer of 1941 represented the greatest concentration of military force the world had seen to that date. Three German army groups had under command 80 infantry divisions, 18 Panzer divisions and 12 motorised divisions, while behind them waited another 21 infantry, two Panzer and one motorised divisions; in reserve: some two million men, 3200 tanks and 10,000 guns. Already in position by mid June to supply them were enough stores dumps, fuel and ammunition reserves to feed them over a 565 to 645km (350 to 400 mile) advance, and 500,000 lorries waited in massed parks from East Prussia to Romania to rush it forward on demand. To the modern mind the only questionable (indeed alarming) figure to emerge from the tables of statistics among the planning memoranda for Operation "Barbarossa" is that for stabling: 300,000 horses were to play an apparently essential part in this monumental military exercise. A 10.5-cm (4.1 in) gun fires on isolated Soviet troops fighting on 129km (80 miles) west of Kiev. As Guderian and Hoth's Panzer divisions raced north of the Pripet Marshes, vast numbers of Red Army soldiers were left in the Ukraine, exposed to encirclement. The disposition of the army groups (and the directions of their advances) were dictated to a large extent by one inescapable geographical factor, namely the Pripet Marshes, a virtually uncrossable swamp nearly 160km (100 miles) from north to south and 480km (300 miles) from east to west, dividing Belorussia from the Ukraine. Because of this, there could be little contact during the first stage of the operation between Army Group South launched from Lublin towards Kiev and the lower reaches of the River Dniepr, and the two groups to the north. These were Army Group Centre aimed first at Smolensk and then (at least in the minds of the military leaders) at Moscow, and Army Group North launched out of East Prussia first towards Lake Peipus and then Leningrad. Victory in eight weeks It was in the northern sector that the greater weight of the attack lay: 50 infantry, 13 Panzer and nine motorised divisions between the groups and, of the two, Army Group Centre was the stronger. Under the command of the icily aristocrat tic Generalfeldmarschall Fedor von Bock were two infantry armies, the 9th and the 4th, and two Panzer formations, Panzergruppe 3 under General Hermann Hoth and Panzergruppe 2 under General Heinz Guderian. These were the armies whose commanders intended to reduce Napoleon's feat of arms of 129 years earlier to historical obscurity, for they planned to reach Moscow in less than eight weeks and to annihilate the Soviet army in the process. Captured Russian Prisoners. If any of the captives were identified as communists they would have been executed on the spot. In this hope they were encouraged by Hitler, who had assured them 'We have only to kick in the front door and the whole rotten Russian edifice will come tumbling down!' Guderian's first task was to throw his Panzergruppe across the River Bug on each side of the fortress of Brest-Litovsk, capture the fortress and then drive precipitously forward towards the city of Minsk, curving up to it from the south to meet Hoth's spearheads coming down from the north. Thus would the Soviet forces immediately behind their attack fronts be isolated in a huge cauldron in which, once their supplies had run out, they would have little alternative but to surrender.