Burnside was defeated at _Fredericksburg_ (December 10-16, 1862) by purely defensive tactics, but Lee had intended to follow up his victory by a decisive counter-blow, which Burnside escaped by extricating the Army of the Potomac before the blow fell. Success, even to the limited degree achieved by Meade or Lee, seldom follows the adoption of purely defensive tactics. "There is no such thing as an 'impregnable position,' for any position the defence of which is merely passive is bound to be carried at last by a manoeuvring enemy" (Marshal Foch).
THE OFFENSIVE BATTLE.--The Entirely Offensive system has been employed by many of the greatest commanders, including Marlborough at _Blenheim_ (August 2, 1704), _Ramillies_ (May 23, 1706), and _Malplaquet_ (September 11, 1709); Frederick the Great, notably at _Leuthen_ (December 5, 1757); Napoleon, Wellington, and Grant, as also by the Prussian generals at almost every engagement in the campaigns of 1866 and 1870-71. The disadvantage of the system is that lack of success may entail not only a local disaster but the wreck and annihilation of the whole army.
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.