When we are talking about the military, the mere concept of strict rules, norms, uniformity and orders are not far. So, it is no wonder that a handbook for the military architect is entirely a collection of various norms and rules concerning the various matters of building a Fort, from the desired location to the accommodation of the infantry.
One could think that such an environment doesn’t leave much room for creativity, but as this book in a way, establishes the framework of five orders of fortifications, one could determine themselves which order could be applied for the specific needs of the location.
As the author Jean du Breuil writes in the preface of the book, he wants to establish new norms of the art of building fortifications for the needs of modern warfare.
In this way his aim is to create the definitive book of fortifications that should serve the King, the noblesse and particularly young gentlemen of the academy who want to gain mastery in this subject to serve the kingdom.
The book is structured into six treaties which each laying out the differences between the orders.
The first treaty establishes the various terms and conditions as well as definitions of fortifications. This gives a rough oversight of the subjects that are discussed in detail in the following treaties. The next treaty concerns itself with the geometry of fortifications in a top-down perspective, in this way this really shows the difference between the medieval and the post medieval way of fortress construction in particular that geometry and mathematic precision are paramount. The subsequent treaty is focusing on the practical implementation of these geometrical fortifications even if the location of those might be irregular, as he calls it. As I understand it, this means all places which are not blessed with an immaculate flat cross-section. This further emphasizes the point that this should be the definite rulebook which can even implement the norms even if the conditions vary. The subsequent treaties concern themselves with the military strategy, specifically in attack and in the defense of the fortress in the changed environment of war with ordnance and firearms.
To conclude it could be said that Jean du Breuil wanted to create orders for fortifications, as Vitruvius did it for the Roman architecture over a millennium ago. Hereby he draws the outline of the archetype for the perfect fortification of his time and sets the standard of what constitutes a good fort in his framework of the 5 orders of Fortifications: the French, the Dutch, the Spanish, the Italian and the Composite order of fortifications.
Quote: « Mais depuis l’invention de la poudre, & celle des Canons, des Pétards, des Fourneaux, & des Mines, on a este oblige de changer cette forte de fortification ancienne […] Or pour se garantir de ces pertes, la nécessite a donné la pensée, & après la pensée, les moyens de se fortifier d’une autre manière, & de telle façon, qu’il ny ait aucun endroit autour de la Place qu` on veut garder, qui ne soit découvert, & yeu d’un ou de plusieurs lieux de l’enceinte de la Place. C`est l’avantage de la fortification moderne, dont je veux vous entretenir en ce Livre, qui porte pour titre, L’ART UNIVERSEL DES FORTIFICATIONS FRANCOISES, HOLONDAISES, ESPAGNOLES, ITALIENNES. Ces quatre ont chacunes leurs Règles & Maximes particulières. Mais j’ajoute, ET COMPOSEES. » (Preface 2+3 page)