The causes of this immense disaster are not far to seek.  They were both political and military.  In staking all on the possession of the line of the Elbe, Napoleon was engulfing himself in a hostile land.  At the first signs of his overthrow, the national spirit of Germany was certain to inflame the Franconians and Westphalians in his rear, and imperil his communications.  In regard to strategy, he committed the same blunder as that perpetrated by Mack in 1805.  He trusted to a river line that could easily be turned by his foes.  As soon as Austria declared against him, his position on the Elbe was fully as perilous as Mack’s lines of the Iller at Ulm.

And yet, in spite of the obvious danger from the great mountain bastion of Bohemia that stretched far away in his rear, the Emperor kept his troops spread out from Koenigstein to Hamburg, and ventured on long and wearying marches into Silesia, and north to Dueben, which left his positions in Saxony almost at the mercy of the allied Grand Army.[384] By emerging from the mighty barrier of the Erzgebirge, that army compelled him three times to give up his offensive moves and hastily to fall back into the heart of Saxony.

The plain truth is that he was out-generalled by the allies.  The assertion may seem to savour of profanity.  Yet, if words have any meaning, the phrase is literally correct.  His aim was primarily to maintain himself on the line of the Elbe, but also, though in the second place, to keep up his communication with France.  Their aim was to leave him the Elbe line, but to cut him off from France.  Even at the outset they planned to strike at Leipzig:  their attack on Dresden was an afterthought, timidly and slowly carried out.  As long, however, as their Grand Army clung to the Erz mountains, they paralyzed his movements to the east and north, which merely played into their hands.

As regards the execution of the allied plans, the honours must unquestionably rest with Bluecher and Gneisenau.  Their tactful retreats before Napoleon in Silesia, their crushing blow at Macdonald, above all, their daring flank march to Wartenburg and thence to Halle, are exploits of a very high order; and doubtless it was the emergence of this unsuspected volcanic force from the unbroken flats of continental mediocrity that nonplussed Napoleon and led to the results described above.  Truly heroic was Bluecher’s determination to push on to Leipzig, even when the enemy was seizing the Elbe bridges in his rear.  The veteran saw clearly that a junction with Schwarzenberg near Leipzig was the all-important step, and that it must bring back the French to that point.  His judgment was as sound as his strokes were trenchant; and, owing to the illusions which Napoleon still cherished as to the saving strength of the Elbe line, the French arrived on that mighty battlefield half-famished and wearied by fruitless marches and countermarches.  Of all Napoleon’s campaigns, that of the second part of 1813 must rank as by far the weakest in conception, the most fertile in blunders, and the most disastrous in its results for France.