At the _Battle of Blenheim_ (August 2, 1704), Marlborough, "the greatest captain of his age," had concentrated his forces with those of Prince Eugene of Savoy the previous day and commanded an army of 56,000 men with 52 guns. He was confronted by the joint armies of Marshal Tallard and the Elector of Bavaria, amounting to 60,000 men with 61 guns. It was necessary for Marlborough to attack before Villeroy joined the enemy, or to withdraw until a more favourable opportunity presented itself. The right flank of his opponents rested on high hills, which were protected by detached posts, and the left flank on the Danube, while opposite the centre was the marshy valley of the River Nebel, with several branches running through the swampy ground. Marlborough decided that a battle {47} was absolutely necessary and he attacked the next day. Like Hannibal, he relied principally on his cavalry for achieving his decisive success, and this predilection was known to the opposing commanders. He attacked the enemy's right and left wings, and when heavily engaged with varying fortunes launched his decisive attack against the centre, where the difficulties of the ground caused it to be least expected. Marlborough lost 5,000 killed and 8,000 wounded. The vanquished armies were almost destroyed, at least 40,000 being accounted for, with 12,000 killed, 14,000 wounded and missing, and 14,000 prisoners. THE DEFENSIVE-OFFENSIVE BATTLE.--The Defensive-Offensive system consists in taking up a position which the enemy must attack, and in delivering a decisive counter-stroke when the adversary has exhausted his strength. This system has been employed in almost every campaign. By such means Napoleon achieved his classic victories of _Marengo_ (June 14, 1800), _Austerlitz_ (December 2, 1805), and _Dresden_ (August 27, 1813); and Wellington his Peninsular victories at _Vittoria_ (June 21, 1813), _Orthez_ (February 27, 1814), and _Toulouse_ (April 10, 1814), in addition to his final triumph at _Waterloo_ (June 18, 1815); and it was the method adopted by Marshal Foch in the decisive campaign of 1918, which endured from March until the Armistice in November.