The Siege of Maastricht, 13 to 30 June 1673, took place during the Franco-Dutch War, when a French army captured the strategic Dutch fortress of Maastricht on the Meuse river.
Siege operations were conducted by Vauban, and is thought to be the first use of a technique known as the "siege parallel", a concept that remained in use until the mid-20th century.
Although the Dutch failed to retake the city in 1676, it was returned under the terms of the 1678 Treaty of Nijmegen.
Background
In the 1667–1668 War of Devolution, France captured much of the Spanish Netherlands and Franche-Comté, but relinquished these gains in the Treaty of Aix-la-Chapelle (1668). This was forced on Louis XIV of France by the Triple Alliance, composed of the Dutch Republic, England and Sweden. His response was to diplomatically isolate the Dutch before making another attempt, paying Sweden to remain neutral, and signing the Secret Treaty of Dover with Charles II of England in 1670.
When the French invaded the Dutch Republic in May 1672, they initially seemed to have achieved an overwhelming victory, capturing the major fortresses of Nijmegen and Fort Crèvecœur near 's-Hertogenbosch and occupying Utrecht without a fight. However, by late July, the Dutch Water Line had stabilised the front lines, while concern at French gains brought the Dutch support from Brandenburg-Prussia, Emperor Leopold and Charles II of Spain. Forced to divide his forces, in August Louis sent Turenne and 50,000 troops to the Rhineland.
Maastricht is located on the extreme eastern edge of the Flanders region, a compact area 160 kilometres wide, the highest point only 100 metres above sea level, and dominated by canals and rivers. Until the advent of railways in the 19th century, goods and supplies were primarily transported by water and campaigns fought over the control of rivers such as the Lys, Sambre and Meuse. Along with Sedan, Namur and Liège, Maastricht is one of a series of strategic fortress cities that control the Meuse valley and bridges over the river. Captured in 1632 from the Habsburgs by Dutch stadtholder Frederick Henry of Orange, its fortifications were considerably expanded until 1645.
Its location on both banks of the Meuse made the town extremely important and it was one of the few garrisoned in peacetime. Dutch engineer Menno van Coehoorn began his career there in 1657, as a young Lieutenant in his father's company. Prior to the 1672 invasion, the French prepared forward supply bases in the Bishopric of Liège and the Dutch responded by concentrating 11,000 mercenaries in Maastricht. They hoped that a prolonged siege would gain them sufficient time to prepare the six Rhine fortresses defending the eastern border of the Republic.
The French reached Maastricht on 17 May 1672. Louis wanted to capture the fortress first, but on advice of Turenne bypassed the main defences and only with ten thousand men occupied the satellites of Tongeren, Maaseik, and Valkenburg. This allowed him to overrun the Rhine fortresses and the entire Republic seemed on the verge of collapse before the Dutch managed to stabilise their position in August. The retention of Maastricht now allowed them to threaten the extended French supply lines. In November 1672, William III of Orange used it as a base for an attack on Charleroi, the French-held city at the start of their supply route, taking most of the garrison with him.
As a result, capturing Maastricht was made the primary objective for the French 1673 campaign. The army was accompanied by Louis XIV, for whom sieges were seen as a propaganda tool. While Louis assembled his forces around Kortrijk, another French army was concentrated in the west for a feint attack against Bruges, to prevent Spanish troops from further reinforcing Maastricht. While officially neutral, the Spanish Netherlands provided the Dutch with financial and diplomatic support, since their occupation was Louis' ultimate aim. The French opened the siege on 13 June.
Advances in siege tactics
Maastricht was the first siege where operations were directed by Vauban, although according to the custom of the time, he remained subordinate to the senior officer present, in this case Louis XIV. Louis had forbidden his generals de Condé or Turenne to be present at the siege to prevent them from sharing in the glory. The King regularly visited the trenches, exposing himself to enemy fire and was closely followed by painters and poets who had to immortalise his exploits for posterity, as well as the court historian Paul Pellisson.
Although commonly remembered for the fortifications he built, Vauban's greatest innovations were in the field of offensive operations. Some years previously his general principles were summarised in Mémoire pour servir d’instruction dans la conduite des sièges et dans la défense des places, published in 1740. This has provided modern researchers with some insights about the general principles Vauban probably applied. The 'siege parallel' had been in development since the mid-16th century but Maastricht saw him bring the idea to practical fulfilment.
Three parallel trenches were dug in front of the walls, connecting the perpendicular assault trenches, the earth thus excavated being used to create embankments screening the attackers from defensive fire, while bringing them as close to the assault point as possible (see Diagram). The transverse parallels allowed a much larger number of troops to participate simultaneously in an assault to overwhelm the defenders, while avoiding choking points that often had led to costly failures. Artillery was moved into the trenches, allowing them to target the base of the walls at close range, with the defenders unable to depress their own guns enough to counter this. Once a breach had been made, it was then stormed. This remained the standard for offensive operations until the early 20th century.
Vauban was unusually sympathetic to the impact of war on the poor, on one occasion requesting compensation be paid a man with eight children whose land was taken to build one of his forts. However, his siege works required large numbers of unpaid workers, with severe punishments for those who tried to evade service. 20,000 local farmers were conscripted to dig his trenches at Maastricht.
Troop strengths
The Treaty of Dover included an agreement by Charles II to supply a brigade of 6,000 English and Scottish troops for the French army. It also contained secret provisions, not revealed until 1771, one being the payment to Charles of £230,000 per year for these troops. While Charles was anxious to ensure Louis felt he was getting value for money, there were considerable doubts as to the brigade's reliability if asked to fight the Protestant Dutch on behalf of the Catholic French. As a result, it formed part of Turenne's force in the Rhineland but several officers, including the Duke of Monmouth and John Churchill, future Duke of Marlborough were present at Maastricht as volunteers and given prominent positions by Louis to gratify his English ally. The attacking forces numbered about forty thousand men.
The garrison was commanded by Jacques de Fariaux, an experienced French huguenot exile in Dutch service. Due to the serious situation of the Dutch, many regiments had been withdrawn from Maastricht after May 1672. In June 1673, eight regiments of States infantry, three regiments of States cavalry, an engineer company and a grenadier company remained. The Dutch troops had been reinforced by a Spanish Division containing a regiment of Italian infantry and two regiments of Spanish cavalry. The defenders totalled about five thousand men. This was about three thousand men below the strength that the city commanders had already in 1671 indicated as the minimum for a successful defence.
Between 1645 and 1672, the fortifications had been completely neglected, falling into disrepair. They largely consisted of earthworks that were susceptible to erosion. Makeshift repairs in 1672 and 1673 had only partly improved the situation. Wooden palisades were constructed to reinforce weak spots. A lunette had been added in front of the vulnerable Tongeren Gate.
Siege
Fortification by besiegers
On 5 June, the first French troops reached Maastricht, advancing towards the west bank of the Maas. That night and early into the morning of the 6th a defender identified as the Baron of Vervix led a cavalry sortie in which he was wounded and captured. Though the exact identity of this officer and his noble family are unknown, reports of his capture were conveyed to the garrison by another prisoner who returned to the fortress on the 11th. Later on the 6th troops from Turenne appeared on the east bank, outside the Wijck suburb. On 7 June, the construction of two ship bridges was started, to the north of the city, to connect both forces. Simultaneously, a host of at least seven thousand peasants began to dig the contravallation and circumvallation, even though no relief army was expected. The defenders that day made a sally, followed by a second sortie on 9 June, killing a limited number of French. On 10 June, Louis XIV arrived. The following day, after the completion of the bridges during the night, he was joined by his brother Philippe I, Duke of Orléans and camped at Wolder, a village to the southwest of the city, in an enormous tent able to accommodate four hundred courtiers. De Fariaux was demanded to surrender the city but refused.
On 13 June, the French began to prepare large amounts of wood and digging materials on the west-side of the city. The north of the fortress was protected by a deep and wide moat, directly connected to the river Maas, while the south was covered by the Jeker rivulet, which would flood trenches. The obvious attack route therefore was from the west, over the high and rocky ridge leading to the ford that had in Roman times been the origin of the settlement. Frederick Henry in 1632 had attacked this side also. The drawback of the location was that deeper trenches of the type Vauban preferred had to be dug through more or less solid rock. This was still feasible, however, because the layers consisted of relatively soft marlstone. In this sector two main gates were present, the Brussels Gate in the north and the Tongeren Gate (Tongersepoort, Porte Tongres) in the south.
Around 14 June, the circumvallation was in principle finished. Due to difficult terrain large gaps remained, which was not seen as a problem as the structure served no real function. In 1632, Frederick Henry's circumvallation had been much more extensive. The same day a third bridge was completed to the south of the city. The French were equipped with sixty-three large caliber cannon. On 16 June, gun batteries were positioned, two in front of the Tongeren Gate and one on the north slope of the St Pietersberg which offers an ideal vantage point over the fortress. The guns, once in place, immediately opened fire, spending three thousand shot in the first six hours. During the entire siege, about twenty-thousand shot were by them fired, out of a total stockpile of fifty-thousand. It now became clear that the Tongeren Gate was the main object. It formed a weak point in the defences as it was protected by a small ravelin only and the city wall behind this was still mediaeval in form, without a full height backing earthwork, though a cavalier was present, the Tongerse Kat. Furthermore, there was only a dry moat to its north. In front of the ravelin a new lunette had been constructed but to obtain the necessary earth, to the south a nearby redoubt protecting the Jeker sluice inlet had been levelled. Vauban later criticised this, claiming that if the redoubt had still be present he had not dared to attack at this point because of its enfilading fire. Such fire was still provided by a large protruding hornwork to the north of the gate and the Groene Halve Maan, a demi-lune to its south.