Again, it must be remembered that the object of a campaign in those days was not necessarily to seek out an enemy and beat him. There were two alternatives prescribed by the best authorities, namely, to fight at an advantage or to subsist comfortably.[261] Comfortable subsistence meant at its best subsistence at an enemy's expense. A campaign wherein an army lived on the enemy's country and destroyed all that it could not consume was eminently successful, even though not a shot was fired. To force an enemy to consume his own supplies was much, to compel him to supply his opponent was more, to take up winter-quarters in his territory was very much more. Thus to enter an enemy's borders and keep him marching backwards and forwards for weeks without giving him a chance of striking a blow, was in itself no small success, and success of a kind which galled inferior generals, such as William of Orange, to desperation and so to disaster. The tendency to these negative campaigns was heightened once more by French example. The French ministry of war interfered with its generals to an extent that was always dangerous, and eventually proved calamitous. Nominally the marshal commanding-in-chief in the field was supreme; but the intendant or head of the administrative service, though he received his orders from the marshal, was instructed by the King to forward those orders at once by special messenger to Louvois, and not to execute them without the royal authority. Great commanders such as Luxemburg had the strength from time to time to kick themselves free from this bondage, but the rest, embarrassed by the surveillance of an inferior officer, preferred to live as long as possible in an enemy's country without risking a general action. It was left to Marlborough to advance triumphant in one magnificent campaign from the Meuse to the sea.