Depots of Supplies, and their Relation to Marches.
The subject most nearly connected with the system of marches is the commissariat, for to march quickly and for a long distance food must be supplied; and the problem of supporting a numerous army in an enemy's country is a very difficult one. It is proposed to discuss the relation between the commissariat and strategy.
It will always be difficult to imagine how Darius and Xerxes subsisted their immense armies in Thrace, where now it would be a hard task to supply thirty thousand men. During the Middle Ages, the Greeks, barbarians, and more lately the Crusaders, maintained considerable bodies of men in that country. Cæsar said that war should support war, and he is generally believed to have lived at the expense of the countries he overran.
The Middle Ages were remarkable for the great migrations of all kinds, and it would be interesting to know the numbers of the Huns, Vandals, Goths, and Mongols who successively traversed Europe, and how they lived during their marches. The commissariat arrangements of the Crusaders would also be an interesting subject of research.
In the early periods of modern history, it is probable that the armies of Francis I., in crossing the Alps into Italy, did not carry with them large stores of provisions; for armies of their magnitude, of forty or fifty thousand men, could easily find provisions in the rich valleys of the Ticino and Po.
Under Louis XIV. and Frederick II. the armies were larger; they fought on their own frontiers, and lived from their storehouses, which were