Trace italienne
From Wikipedia, the free encyclopedia
The trace italienne is a style of fortification that was developed in Italy in the late 15th and early 16th century in response, primarily, to the French invasion of the Italian peninsula. The French army was equipped with new cannons and bombards that were able to easily destroy traditional fortifications built in the Middle Ages.
In order to counteract the power of the new weapons, defensive walls were made lower and thicker. They were built of many materials, usually earth and stone. Another important design modification was the bastions that characterized the new fortresses. In order to improve the defense of the fortress, covering fire had to be provided, often from multiple angles. The result was the development of "star" shaped fortresses.
The design spread out of Italy in the 1530s and 40s. It was employed heavily throughout Europe for the following three centuries. Italian engineers were heavily in demand throughout Europe to help build the new fortifications.
The late 17th century architects Vauban and Menno van Coehoorn are considered to have taken the form to its logical extreme. "Fortressess... acquired ravelins and redoubts, bonnettes and lunettes, tenailles and tenaillons, counterguards and crownworks and hornworks and curvettes and fausse brayes and scarps and cordons and banquettes and counterscarps... that baroque profusion."
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[edit] Construction
Due to the massive expense of constructing these new fortifications, they were often improvised from earlier defences. Medieval curtain walls were torn down and a ditch was dug in front of them. The earth used from the excavation was piled behind the walls to create a solid structure. While purpose built fortifications would often have a brick fascia because of the material's ability to absorb the shock of artillery fire, many improvised defences cut costs by missing this stage out and instead opted for more earth. Improvisation could also consist of lowering medieval round towers and infilling them with earth to strengthen the structures.
It was also often necessary to widen and deepen the ditch outside the walls to create a more effective barrier to frontal assault and mining. Engineers from the 1520s were also building massive gently-sloping banks of earth called glacis in front of ditches so that the walls were almost totally hidden from horizontal artillery fire. The main benefit of the glacis was to deny enemy artillery the ability to fire point blank. The higher the angle of elevation, the lower the stopping power.
An example of the great expense of updating fortifications is the city of Siena, which went bankrupt in 1544 attempting to update its city walls.
[edit] Notable Instances
The first key instance of Trace Italienne was at the Papal port of Civitavecchia where the original walls were lowered and thickened because the stone tended to shatter under bombardment.
The first major battle which truly showed the effectiveness of Trace Italienne was the defence of Pisa in 1500 against a combined Florentine and French army. The original medieval fortifications beginning to crumble to French cannon fire, the Pisans constructed an earthen rampart behind the threatened sector. It was discovered that the sloping earthen rampart could be defended against escalade and was also much more resistant to cannon fire than the curtain wall it had replaced.
The second siege was that of Padua in 1509. A monk engineer named Fra Giocondo, trusted with the defence of the Venetian city, cut down the city's medieval wall and surrounded the city in a broad ditch that could be swept by flanking fire from gunports set low in projections extending into the ditch. Finding that their cannon fire made little impression on these low ramparts, the French and allied besiegers made several bloody and fruitless assaults and then withdrew.
[edit] Effectiveness
Despite the advantages of these fortresses over earlier designs, "most first-class fortresses could be taken in roughly six to eight weeks." In his writing "The Art of War" Machiavelli said:"There is no wall, whatever its thickness that artillery will not destroy in only a few days"
Yet Machiavelli was wrong. According to Geoffrey Parker in this article 'The military revolution 1560-1660: a myth?', the appearance of the trace italienne in early modern Europe, and the difficulty of taking such forifications, resulted in a profound change in military strategy. 'Wars became a series of protracted sieges', Parker suggests, and open-pitch battles became 'irrelevant' in regions where the trace italienne existed. Ultimately, Parker argues, 'military geography', in other words the existence or absence of the trace italienne in a given area, shaped military strategy in the early modern period. This is a profound alteration of the military revolution thesis originally proposed by Michael Roberts in his inaugural lecture delivered at the Queens University, Belfast, in 1955.
