Vauban was one of the most famous fortress builders for Maastricht. In 1673, however, the outer works proved unable to withstand Vauban's new method of attack. The battle took place mainly in the forecourt of the "Gate of Tongres," where d'Artagnan, (the eponymous hero from the book "The Three Musketeers" by Alexander Dumas) fell.
A plan by Vauban for complete modernization, which included securing the heights around Maastricht, was not carried out. But when Maastricht became part of the Republic of the Seven Provinces again in 1678 as a result of the peace of Nijmegen , the famous fortress builder had reinforced the weak points by lunettes and the southern inundation system between Meuse and Jeker, almost renewed and further expanded.
The Jeker Canal
The channel in the city canal, which was supposed to bring the water from the Jeker, beyond the Hoge Fronten to the so-called Lage Fronten, was replaced by a vaulted aqueduct of 1165m. The so-called Jeker Canal, which was recovered virtually undamaged in 1943.
From the last quarter of the 17th century, the fortification system expanded like an oil slick. This occurred, first under the pressure of the wars against France between 1688-1713. And then, against the background of the siege of 1748 and the failure to resist, of the barrier towns in the Southern Netherlands, for national defense.
George Frederick, Count of Waldeck
In the first phase, under the supervision of Governor George Frederick, Count of Waldeck, especially the High Fronts were reinforced by new bastions and other fortifications. The plans came from the military engineer Baron van Dopff, who became governor in 1706.
Vauban
In the years 1673-1678, the defensive capability of the fortress was raised to a higher level dor Vauban. He eliminated a number of gaps and deficiencies, including the construction of lunettes, (d'Orleans 1674, D'Estrades 1674, Lunette de la Reine 1674 Lunette du Roi 1674 Lunette de Dauphin 1674,Lunette Condé and lunette du Royale 1674) and the improvement of the southern inundation system and the new works outside the Boschpoort (raveline Boschpoort and raveline Zobel). Bastion Pierre was constructed on the south side of the fortress.
Baron Van Dopff
Even after the departure of French troops, work on the fortress resumed under the threat of war. From van Dopff are known, among others: bastion Saxony (1688), bastion Holstein 1688 , bastion England (1688), bastions Waldeck (1690) Dopff (1699) Fort St. Peter (1701), The most important work of this period is Fort St. Peter against the north slope of St. Peter's Mountain, a creation of Baron Van Dopff, from the years 1701-1702, which was to prevent repetition of the shelling, from the mountain in 1673, and could take attacks on the western sector of the fortress in the flank.
After half a century of stagnation, war damage and neglect, a major modernization followed after 1794. These were carried out under the supervision of Governors Hobbe (Baron van Aylva) and Charles Prince of Nassau-Weilberg according to "general projects" drawn up by the directors of fortifications Pieter De la Rive (1746-1771) and Carel Du Moulin ( 1772-1774). We refer to Fort Saint Peter for further details.
Plan de La Rive
After the Peace of Aachen, large-scale plans were made by the engineer de la Rive , which, however, did not come to fruition in their entirety. De la Rive's plan maintained as much as possible the existing situation, but tried to eliminate the deficiencies by demolishing useless fortifications, such as certain hornworks and by renovating the old and building new fortifications. In the years 1764-1771, dozens of bastions, lunettes, couvrefaces and other outworks were constructed. Pieces of the Wilhelmina bastion on the Jeker and of the lunette Saint-Pierre on the Meuse still remind us of this fruitful building activity. In the meantime, the fortification system had expanded so much that it could no longer be defended by a garrison of normal strength.
Plan Du Moulin
Du Moulin's general modernization plan (1772-1775) provided for the streamlining and simplification of the fortification belt through the increased use of stone for the cladding walls and other building elements. Vaulted gates, the so-called sorties and caponnieres (bombproof galleries covering the sorties and dry moats), were to allow effective defense if the enemy penetrated "this fortress outside the walls". Thus, the Du Moulin Line was created with the structure of an envelope, connected to the city by sorties. This line extended from Waldeck bastion to Holstein bastion.