The neglect of the Prussians to place their country in a state of military defence, previous to declaring war against Napoleon in 1806, had a most disastrous influence upon the campaign. Napoleon, on the other hand, occupied and secured all the important military positions which he had captured in the preceding campaign. "The Prussians," said he, "made no preparations for putting into a state of defence the fortifications on their first line, not even those within a few marches of our cantonments. While I was piling up bastion upon bastion at Kehl, Cassel, and Wesel, they did not plant a single palisade at Magdeburg, nor put in battery a single cannon at Spandau." The works on the three great lines of the Oder, the Elbe, and the Weser, had they been properly repaired, garrisoned, and defended, were sufficient to have held in check the French, even after the great victory of Jena, till the newly-organized forces, acting in concert with the Russian army, could re-establish the Prussian monarchy in its ancient greatness. Profiting by the neglect of the Prussians, Napoleon seized upon the great defensive works of the country, which, to his great joy, were readily surrendered into his hands by the old and inefficient generals who commanded them; and French garrisons were almost immediately established in the fortresses of Stettin, Custrin, Glogau, Magdeburg, Spandau, Hameln, Nieubourg, &c. "Spandau," said he in the 19th Bulletin, "is an inestimable acquisition. In our hands it could sustain two months of operations. But such was the general confusion, that the Prussians had not even armed its batteries." The possession of these fortifications inclined the scale at Eylau. All the historians of the war notice their influence on the campaigns of Friedland and Tilsit. These Prussian fortresses were retained by Napoleon at the treaty of Tilsit. The campaign of 1809 proved the wisdom of this policy, as they effectually prevented Prussia from joining Austria in rekindling the flames of war. And again in 1813, these works might have produced a decided influence on the campaign, had not the political perfidy of Austria, and the treason of the French generals, prevented Napoleon from profiting by the advantages of his position. The influence of the fortifications of Spain upon the Peninsular campaigns has often been alluded to by historians. Those works which had been given up to Napoleon previous to the opening of hostilities, contributed very much to the success of his arms; while those which had been retained by Spain and her allies contributed in an equal degree to fetter and embarrass his operations. Some of these, like Saragossa, Tarragona, Gerona, Tortosa, &c. &c., with their broken walls and defective armaments, kept the enemy in check for months; and, by compelling the French to resort to the tedious operations of sieges, did much to weaken the French power in the Peninsula.