Montesquieu

In the time of Charlemagne one was obli­ged under great penal­ties to show up when cal­led to any war wha­te­ver ; no excu­ses were accep­ted, and the count who exemp­ted anyone would him­self have been puni­shed.1 But the treaty of the three bro­thers2 pla­ced a res­tric­tion on this3 which, so to speak, took the nobi­lity out of the king’s hand : they were no lon­ger obli­ged to fol­low the king to war except when that war was defen­sive. They were free, in others, to fol­low their lord, or to attend to their busi­ness.

The death of a hun­dred thou­sand Frenchmen in the bat­tle of Fontenay4 made what was still remai­ning of the nobi­lity think that they would ulti­ma­tely be exter­mi­na­ted by their kings’ pri­vate wars over their divi­sions, and that their ambi­tion and their jea­lousy would cause the spilling of all the blood still left to shed. They made the law that the nobi­lity would be requi­red to fol­low prin­ces to war only when it was a mat­ter of defen­ding the state against a foreign inva­sion. It was in effect for seve­ral cen­tu­ries.5

Capitulary of the year 802, art. 7, Baluze ed., p. 365.

Apud Marsnam, year 847, Baluze ed., p. 42.

Volumus ut cujuscumque nostrum homo in cujuscumque Regno sit, cum seniore suo in hostem, vel aliis suis utilitatibus pergat, nisi talis Regni invasio quam Lamtuveri dicunt, quod absit, acciderit, ut omnis populus illius Regni ad eam repellendam communiter pergat, art. 5, ibid., p. 44.

[Battle of Fontenoy-en-Puisaye, 25 June 841.]

See the law of Guy king of the Romans, among those that have been appended to the Salic law and the Leges Langobardoroum, tit. 6, §2 in Echard.