L’Art de la construction de fortifications

Welsch was given the task of enlarge and finish the fortress Mainz under Elector and Archbishop Lothar Franz von Schönborn. Furthermore, he was part of the fortresses Rosenberg (Kronach), Forchheim, Kehl and the citadel Peterberg (Erfurt). Moreover, he planned and built several castles, palaces, government buildings and churches.

Conquered the fortress Coevorden in 1680 and modernised it. Was defeated by attacking Vauban when defending fortress Namur. IN 1695 he managed the besiegement for reconquest of Namur and planned the reconstruction of fortified city Mannheim in 1698. He also wrote an often-read book about fortification architecture in lower lands, with steel work until the 19th century and developed a special mortar of besiegement use which was first used in World War I.

In 1695 Verboom and Menno van Coehorn operated in the reconquest of Namur. Later he oversaw the defence systems of Antwerp. In 1709 he was named general engineer of the Kingly Spanish Army. In 1710 he was taken captive during the battle of Almenar and incarcerated until 1712. In 1713 he was an active part of the reconquest of Barcelona and lived there from 1718 in order to oversee the construction of the citadel. Moreover, he worked in Ceuta, Malaga, Sevilla and Gibraltar.

Sanmicheli was the most important fortification architect of his times. After is entry in the service of the republic Venice in 1528 he was part of the enlargement and improvement of almost all Venetian fortifications facilities. Under his management the Lido in Venice was first fortified, the fortified cities Brescia, Bergamo and Zadar were expanded. He was also part in fortifications on Crete, Corfu and realised among others the wonderful Porta Nuova in Verona.

Specklin learned in Strasbourg the good profession of Seidenstickers (lat. Acupictor) and got in his years of travel in Hungary to the fortress construction in Komorn. Later he worked in Vienna and Antwerp as well as in his hometown Strasbourg.