The Thirty Years' War began in the German states as Europe’s major powers backed either the northern Protestant Union or the southern Catholic League.  As the war progressed, religion receded in importance, replaced by a dynastic struggle between the French Bourbon and the Spanish and Austrian Habsburgs. Although the economic and social effects of this war are still being debated, many historians believe that the German economy was ruined, and the German population declined precipitously. The Thirty Years’ War was the most destructive conflict Europeans had yet experienced, leading to a new phase of European warfare often referred to as the “Age of Dynastic Warfare” (1648-1789) where the standing royal dynastic army, complete with standardized uniforms and weapons, gradually replaced warfare conducted with the use of large mercenary forces. The Thirty Years’ War ended with the Peace of Westphalia in 1648 and left the kingdom of France, under the long-reigned “Sun King” Louis XIV (r.1614-1715), as the most powerful state in Western Europe. To defend his realm, Louis commissioned Sebastien Le Prestre de Vauban (1633-1707) to upgrade old fortified towns and cities and create new and innovative fortifications across the French kingdom. His seminal work, On Siege and Fortification (Traité des sièges et de l'attaque des places, 1737) shaped the science of European fortification and siegecraft for generations.

Right: Portrait of Sébastien Le Prestre de Vauban (1633-1707), a French military architect and politician who served the French monarch Louis XIV as a senior military advisor. Oil on canvas by Hyacinthe Rigaud (1659–1743).  Click to enlarge.

King Louis XIV of France (the “Sun King” r.1614-1715) dominated the events in Western Europe during his seven decade long reign, creating the kingdom’s prototypical Absolute Monarchy later referred to as the Ancien Régime. France’s dominance was due in part to its possession of the most powerful European army of the era, one that reached a peak strength in 1709 at 400,000 troops, the largest European army before the French Revolution. Desiring to expand his influence and territory in Western Europe, Louis XIV was responsible for five major wars during his reign, including the War of Devolution (1667-1668), the before mentioned Dutch War, the War of the League of Augsburg (1688-1697), the Nine Years’ War (1688-1697), and the War of Spanish Succession (1701-1714). The chief architect of Louis XIV’s powerful army was François-Michel le Tellier, the Marquis de Louvois (1641–1691), who served the Sun King as Minister of War from 1662 until his death in 1691. During his tenure, Louvois enacted numerous military reforms that transformed the French army into the most formidable force in Europe. These included the appointment of inspector-generals to audit the army’s accounts, eliminate waste, and reduce internal corruption; the creation of duty lists that clarified the specific responsibilities for each rank of officer, from lieutenant to marshal; significant improvements in training and discipline; and the development of a more efficient logistical system that provided tents, mobile bakeries, and streamlined procedures for requisitioning food and fodder during campaigns. To further sustain the army in the field, Louvois mandated that essential supplies, such as spare arms, ball, and powder, to be stored in fortress magazines located in frontier zones, thereby reducing reliance on the vulnerable and cumbersome logistical trains that had dominated European warfare for centuries.[1]  These military reforms also came in a time when infantry tactics were changing due to the adoption of the flintlock musket as a replacement for the less efficient matchlock firearm. At the same time, infantry began to abandon the pike in favor of variations of the bayonet, evolving from the plug, ring, to finally the socket bayonet, that helped eliminate the use of pikemen on the battlefield by the beginning of the eighteenth century. This new technology further standardizing the European infantryman into a combination fire and shock soldier. The man given credit for the invention of the socket bayonet (baïonnette à douille) is Sebastien Le Prestre de Vauban (1633-1707), the greatest military engineer of his age.[2]

Born in Burgundy, Vauban received his education at the age of ten at the Carmelite college in Semur-en-Auxois, where he was taught mathematics, science and geometry. At the age of eighteen, Vauban enlisted as a cadet in the French army during the Fronde (1651), serving with the Prince de Conde first in France, and later in exile fighting in the Spanish Netherlands for the Spanish. After receiving a royal pardon in 1653, he served with distinction as a royal engineer, earning the rank of King’s Engineer in 1655. The Marquis de Louvois made Vauban director or Commissary-General of Fortifications in 1678, and it is in this capacity he oversaw several sieges during the Dutch War, War of the League of Augsburg, and the Nine Years’ War. Requested by the Sun King to fortify France, Vauban drew up a plan to build a ring of new fortresses that, along with defensive improvements of existing fortresses, would serve to protect the kingdom’s southwestern, western, northern and eastern frontiers and forward operating bases for offensive operations into enemy territory.[3] Described as the “Fence of Iron” (Barrier de Fer), these fortresses were large enough in both physical and garrison size to require an invading army to divide his forces to invest multiple forts in a region, and close enough to offer mutual support and relief during sieges.[4]  These fortresses are spread across France and occupied frontier zones and include citadels (citadels of Arras and Besancon), mountain forts (Briançon, Mont-Dauphin, Mont-Louis), coastal forts and tower systems (Camaret-sur-Mer and Saint-Vaast-la-Hougue), a fortified island (Saint-Martin-de-Re), and a brilliant new walled city (Neuf-Brisach), designed but not finished during his lifetime. In all, Vauban directed the construction of both new and existing fortresses, perhaps 160 in all, throughout the kingdom and frontier zones before his promotion to Marshal of France and semi-retirement in 1703.[5]

As an established military architect, Vauban used his understanding of defensive fortifications to improve the science of offensive siege operations through the implementation of his “theory of parallel attack,” essentially a series of parallel trenches advancing toward the fortification under the cover of artillery fire, siege tactics later adopted throughout Europe. He was also responsible for what was referred to as the three “systems of fortification” which evolved throughout his professional life revolutionizing fortress design in the seventeenth century. Drawing on a half-century of military service, these important offensive and defensive military concepts were published in his On Siege and Fortification (De l’attaque et de la defense des places) written at the end of his life between 1705 and 1706 during the last decade of Louis XIV’s reign. It was later published for the first time in French in 1737 and then in English in 1748 as The New Method of Fortification.[6]

Vauban's On Siege and Fortification describes in detail his “Theory of Parallel Attack,” first put into practice during the Dutch War at the 1673 siege of Maastricht in the Netherlands. This theory advocates infantry and artillery leapfrogging in 200 yard increments towards the base of a fortress wall using both parallel and connected trenches. Understanding the limited ranges of seventeenth century siege guns at around 600 yards, Vauban placed the French guns at this distance from the weakest flank of the enemy fortress and then dug a long trench behind the guns as a base for the infantry. From here musketeers can protect the artillery from attack by enemy sorties, while at the same time provide cover for French sappers digging zigzag trenches (as protection against enemy raking cannon fire) forward towards the fort. 

RIGHT: Vauban’s plan for the new fortified town of Neuf-Brisach, built on the orders of Louis XIV after the loss of Vieux-Brisach on the Rhine.  Click to enlarge.

Once the zigzag trench had moved forward about 200 yards, another trench was dug parallel to the fortress wall, advancing the siege line with both infantry and artillery moving up to the new position. The whole process was repeated a second time, which brought the sappers within range of musket fire from the enemy ramparts, requiring added defensive protections in the form of a protective roof and the use of wheeled mobile sheds. Once the third parallel trench was successfully established, the siege artillery was brought forward for a direct bombardment on the walls.[7] Using Vauban’s Theory of Parallel Attack the formidable walled city of Maastricht fell to the French army in just thirteen days. He went on to successfully besiege Valenciennes (1677) and Ypres (1678) during the Dutch War.[8] This method quickly became the standard tactic used in siege warfare across Europe, proving reliable and easily adapted to different fortifications and their surrounding terrain.

Vauban also improved fortification design during his tenure as Commissary-General of Fortifications for Louis XIV. In response to the vulnerabilities of tall medieval fortresses and urban fortifications, late fifteenth and sixteenth century military engineers decreased the height of the walls in order to provide a less visible target, while increasing their thickness to provide greater strength against improving gunpowder artillery and to support the defender’s own cannons, creating what modern scholars refer to as trace italienne (“Italian outline”) or sometimes “bastion” or “artillery” fortifications. Building on the theories of his predecessor, Blaise de Pagan (1604-1665), Vauban improved on the older trace italienne design through the construction of larger fortifications and the addition of exterior walls and outer works.[9] He introduced the glacis, a sloping area around the fortress concealing the covered ways and the counterscarp from enemy artillery fire.  Angled bastions were also added to provide converging fields of fire at every potential point of attack, creating a "killing zone" for an enemy advancing on the fortification.[10]

These ideas evolved throughout his life, although they were classified after his death into three systems of fortification. The “First System” used the defensive theories of Pagan to set up a system of bastions which mutually protected each other. Each face of the structure was protected from enemy fire by the neighboring bastion. The “Second System” increased the number of defensive walls, creating an external wall Vauban described as “the combat wall” facing outward, designed with polygonal shaped bastions and ravelins, and an internal wall called “the safety wall” made up of bastioned towers built on the ramparts to provide a second line of defense.

LEFT: The town of town of Neuf-Brisach today. Click to enlarge.

These bastions formed independent defensive belts around the body of the stronghold and the ramparts. As the external wall was higher than the internal wall, the enemy could only fire on the first wall and could not see the defensive preparations taking place in the second hidden wall, a design contrary to classical and medieval fortifications in use for millennia. Each element in the defensive system offered supporting fire and played a role in creating a defense-in-depth. The “Third System” is an improvement on the defense-in-depth of the “second system” through the use of additional ravelins, extending his defense-in-depth philosophy. However, this third system was only used at the fortress of Neuf Brisach, completed after Vauban’s death, and many modern scholars do not consider it to be an independent system as it was never copied again by any other military engineers.[11]

Vauban’s principles on siegecraft and fortification exemplified by his Theory of Parallel Attack and Three Systems of Fortification centered on careful operational planning, rationally occupying terrain either offensively as besiegers or defensively as the besieged through the construction of improved fortifications, and using artillery wisely in both pursuits. Furthermore, his prominence in the court of Louis XIV raised the status of military engineering in Early Modern warfare to a place it had not held since the classical age, entrenching military engineering as both an honorable pursuit and necessary science in future combat operations. In fact, On Siege and Fortification was still being read as late as 1830 as a practical guide in military academies in Europe and the United States.[12] Today, there are twelve UNESCO World Heritage sites associated with the work of Vauban, a testimony to his extraordinary achievements as military engineer and military theorist.

Endnotes 

[1]  Larry H. Addington, The Patterns of War Through the Eighteenth Century (Indiana University Press, 1990), 92. Also see John A. Lynn, “Food, Funds, and Fortresses: Resource Mobilization and Positional Warfare in the Campaigns of Louis XIV” in Feeding Mars: Logistics in Western Warfare from the Middle Ages to the Present, ed. John A. Lynn (Westview, 1993), 105.

[2]  James Falkner, Marshal Vauban: Louis XIV's Engineer Genius (Pen & Sword Books, 2020), 197-199.

[3]  Falkner, Marshal Vauban,  31-32.

[4]  Addington, The Patterns of War Through the Eighteenth Century,  92.

[5]  For a list of new and existing fortresses associated with Vauban, see Paddy Griffith, The Vauban Fortifications of France (Osprey, 2009),13-20.

[6]  Sébastien Le Prestre de Vauban, The New Method of Fortification, trans Abel Swall (Gale Eco, 2010).

[7]  Ostwald, Vauban under Siege,  57-58. Also see Falkner, Marshal Vauban,  61-66.

[8]   Falkner, Marshal Vauban, 159-160, 164-167.

[9]  Griffith, The Vauban Fortifications of France, 21, 30, 40.

[10]  For an excellent break down of  Vauban’s principles of defense and features of fortress, design, see Griffith, 39-55.

[11]  Ibid, 24-25.

[12]  Martin van Creveld, A History of Strategy: From Sun Tzu to William S. Lind (Castalia House, 2015), 40. 

Bibliography 

Primary Sources

Vauban, Sebastien Le Prestre de. The New Method of Fortification. Translated by Abel Swall. Gale Eco, 2010.

Secondary Sources

Addington, Larry H. The Patterns of War Through the Eighteenth Century. Indiana University Press, 1990.

Falkner, James. Marshal Vauban: Louis XIV's Engineer Genius. Pen & Sword Books, 2020.

Griffith, Paddy. The Vauban Fortifications of France. Osprey, 2009.

Lynn, John A. Feeding Mars: Logistics in Western Warfare from the Middle Ages to the Present. Westview, 1993.

Van Creveld, Martin. A History of Strategy: From Sun Tzu to William S. Lind. Castalia House, 2015.