The “petite guerre“ was a type of warfare consisting in skirmishes and ambushes which, between sieges and battles, filled the theatre of operations during the conventional wars – it could be told a “war in detachments” too. The first treatises on the art of the “petite guerre” were published in France, from the mid-eighteenth century onwards. The locution “petite guerre” wasn’t translated into English in the eighteenth century, even in treatises published in Great-Britain or America (on the contrary, it was translated into German). In order to describe the “petite guerre”, the first theorists drew the lesson of the French defeats in Bohemia during the War of the Austrian Succession (1742), but also relied on the French victories in Flanders from 1744 to 1748. The evolution of the French “petite guerre” into an art definitely dates back to the Flanders campaigns, thanks to Marshal de Saxe, who masterfully coordinated his various actions so as to make the “petite guerre” subservient to a global strategy. This is why it is most relevant to study the case of these campaigns ‒ re-examined from the specific perspective of the “petite guerre”. Next to a case study, the book makes a thorough analysis of the thoughts on the “petite guerre” throughout the eighteenth century, in France and in the most important countries of Europe; with a special chapter on the thoughts in Great-Britain – and the case of British light troops in Flanders in 1747 –, because this topic had not been dealt with before. However, the topic goes beyond the mere scope of a tactical study. By showing the impact of the “petite guerre” on civilians and on the activity of the provincial administration, by analysing the government policy towards light troops (the light troops were the specialists of the “petite guerre”), by approaching the opinions of Parisian society (and of the elite as a whole) towards such military tactic and the troops specialising in it, what is at stake is also the possibility to grasp the ideas and sensitivity of society towards the “petite guerre”. This work is thus a contribution to a larger study ‒ that of an era's mentalities towards military issues.