The numbers of the guerillas varied at different times, as the chiefs rose or declined in reputation, and as they possessed the means of maintaining their followers. Some led small flying armies of two thousand and upwards. Others, or the same chiefs under a reverse of fortune, had only ten or twenty followers. The French often attempted to surprise and destroy the parties by which they suffered most, and for that purpose detached moveable columns from different points, to assemble on the rendezvous of the guerilla. But, notwithstanding all their activity and dexterity on such expeditions, they rarely succeeded in catching their enemy at unawares; or if it so happened, the individuals composing the band broke up, and dispersed by ways only known to themselves; and when the French officers accounted them totally annihilated, they were again assembled on another point, exercising a partisan war on the rear, and upon the communications, of those who lately expected to have them at their mercy. Thus invisible when they were sought for, the guerillas seemed every where present when damage could be done to the invaders. To chase them was to pursue the wind, and to circumvent them was to detain water with a sieve. Soult had recourse to severity to intimidate these desultory but most annoying enemies, by publishing a proclamation [May 9] threatening to treat the members of the guerillas, not as regular soldiers, but as banditti taken in the fact, and thus execute such of them as chanced to be made prisoners. The chiefs, in reply to this proclamation, published a royal decree, as they termed it, declaring that each Spaniard was, by the necessity of the times, a soldier, and that he was entitled to all military privileges when taken with arms in his hands. They therefore announced, that having ample means of retaliation in their power, they would not scruple to make use of them, by executing three Frenchmen for every one of their followers who should suffer in consequence of Soult's unjust and inhuman proclamation.[46] These threats were fulfilled on both sides. It is said, a horrid example of cruelty was given by a French general, who in a manner crucified, by nailing to trees, eight prisoners, whom he had taken from the guerillas of the Empecinado. The daring Spaniard's passions were wound up too high to listen either to pity or fear; he retaliated the cruelty by nailing the same number of Frenchmen to the same trees, and leaving them to fill the forest of Guadarama with their groans. But these excesses became rare on either side; for the mutual interest of both parties soon led them to recur to the ordinary rules of war.