There was therefore, in consequence of the varying strength of the regiments, no regularity or system in the brigading of the French troops in Spain: in one brigade there might be five or six isolated battalions, each belonging to a separate regiment; in another three from one regiment and two from a second; in a third four from one regiment and one from another. Nor was there any fixed number of battalions in a brigade: it might vary from three (a very unusual minimum) up to nine--an equally rare maximum. Six was perhaps the most frequent number. A division was composed of two, or less frequently of three, brigades, and might have any number from ten up to sixteen or eighteen battalions--i.e. it varied, allowing for casual losses, from 6,000 to 10,000 men. This irregularity was part of Napoleon’s system: he laid it down as an axiom that all military units, from a brigade to an army corps, ought to differ in strength among themselves: otherwise the enemy, if he had once discovered how many brigades or divisions were in front of him, could calculate with accuracy the number of troops with which he had to do. Much confusion is caused, when we deal with Napoleon’s army, by the strange system of numeration which he adopted. The infantry, whether called ‘line regiments’ or ‘light infantry regiments,’ were drilled and organized in the same way. But the Emperor had some odd vagaries: he often refused to raise again a regiment which had been exterminated, or taken prisoners _en masse_. Hence after a few years of his reign there were some vacant numbers in the list of infantry corps. The regiments, for example, which were garrisoning the colonies at the time of the rupture of the Peace of Amiens, fell one after another into the hands of the English as the war went on. They were never replaced, and left gaps in the army list. On the other hand the Emperor sometimes raised regiments with duplicate numbers, a most tiresome thing for the military historian of the next age. It is impossible to fathom his purpose, unless he was set on confusing his enemies by showing more battalions than the list of existing corps seemed to make possible. Or perhaps he was thinking of the old legions of the Roman Empire, of which there were always several in existence bearing the same number, but distinguished by their honorary titles. Those who wish to read the story of one of these duplicate regiments may follow in the history of Nodier the tale of the raising and extermination of Colonel Oudet’s celebrated ‘9th Bis’ of the line[79]. [79] Nodier, _Souvenirs de la Révolution_, ii. 233-5.