Military perspective, also known as cavalier perspective, combines illusionistic depth and orthographic measure to produce a depth dimension that both aids the identification of the monument in a satisfying manner and at the same time contains measured depth using the same scale as the frontal plane. In the early modern period, the employment of parallel perspective used to draw machines and architecture merged with the latest developments in orthographic perspective to create varieties of non-converging perspective that could be read rigorously with a single unit of measure.

Although one can argue that the basics of military perspective were already present in the fifteenth century, military perspective as it is most rigorously understood maintains consistent measure into the third (or “z,” to complement the “x” and “y”) dimension, and this is first seen in the sixteenth century. Preserving the ground line and elevation and extending parallel lines into depth created “oblique” perspective, where parallel orthogonals simply connect at the ground line. In addition, other varieties – such as one preserving symmetry (a primitive form of isometry) – were developed under the umbrella of “military” or “cavalier” perspective (so-named because it appears to be drawn from an elevated gun platform called in Italian a *cavaliere*. This new perspective allowed for rapidly imagining, studying, and calculating the costs of fortifications.

Military perspective follows the older mode of drawing machines that can be summarized as “one machine, one drawing” (McGee). Such drawings maximized recognition of the whole and the perception of its parts from an elevated viewpoint. This medieval approach was developed by Taccola, Francesco di Giorgio and Leonardo da Vinci in the fifteenth century. However, these early drawings were not metrically accurate. As Massimo Scolari (215-246) has argued in seminal essays, the basis of military perspective emerges first in mathematical proofs and can be inferred in architectural treatises when one can read dimensions from uniformly sized blocks or bricks. In these cases, the mode of representation already incorporates a depth orthogonal of approximately 45 degrees to the frontal plane.

Mature military perspective was born through the reforms to orthography by Bramante, Leonardo, Raphael and Antonio da Sangallo the Younger. While orthography for buildings and ichnography for cities was taken for granted, the depth dimension could become more nearly accurate, as in Francesco Paciotto’s map of Rome from 1557, based in large part on the ichnographic map of Leonardo Bufalini (1551).

When does intuitive or pseudo-military architecture begin to incorporate a sense of rigorous depth? In the 1520s and 1530s, Antonio da Sangallo the Younger and his collaborators were measuring the Aurelian wall with a great deal of accuracy. When he, or one of his family members, sought to illustrate parts of Vitruvius on military architecture, they resorted to what is essentially military perspective. The following illustration of a curtain wall (on the right), though it lacks dimensions because it is merely illustrating a point, can be read in elevation and depth.

As far as theoretical elaboration, it was Scolari, again, who pointed to a textual comment by Giovan Battista Belluzzi (1598 but written c. 1545), a Marchegian military engineer working for the duke of Florence, who wrote of a “perspective suited to practice” (*quella prospettiva che serve alla pratica*). “We must,” he explained, “see the whole thing intact, detached, and measured” (*havemo di bisogno veder la cosa tutta intera, & spiccata, & misurata*, p. 3). Scolari however did not use Belluzzi’s illustrations to bolster his arguments. His autograph drawings in his autograph manuscript in Anghiari show nevertheless that he was one of the most rigorous early adopters of military perspective (Lamberini).

In his 1564 treatise, annotated by Girolamo Maggi, Castriotto used military perspective perhaps for the first time in print. Contemporary treatises by Zanchi (*Del modo di fortificare le città*, 1554) and Cataneo (*Opera nuova di fortificare, offendere et difendere et far gli alloggiamenti*, 1564) continue to use orthography or slightly receding perspective orthogonals. Yet Castriotto – who apparently knew Belluzzi from the duchy of Urbino, suggesting a common practice – reproduced images like 27 recto below, which rigorously extend parallel lines from the ground and elevation lines. In this section, he introduced the term “soldierly perspective” (*prospettiva soldatesca*) and framed it as a less technical than “prospettiva.” Military perspective, then, served both as more intuitive and less difficult than perspective. The connection to measure is clear when Castriotto presents cross-sections of bastions with graphs, which aid the measurement of earth fill or bricks.

Calculating cost had been a standard problem of construction from the late middle ages on. Using standard quantities of brick, sand and mortar, one could calculate per unit of measure and architects like Baldassare Peruzzi used orthographic plans to help calculate costs (Huppert). The sloping scarp of the new curtains and bastions, in addition to the irregularity of footprints due to the terrain, complicated matters and Castriotto’s procedure shows how issues of cost can clearly be tackled with his new kind of perspective. He writes of the figure below: “In this view one sees half a cortina, a half bastion, and a half cavalier, and above it I placed these profiles and plans each assigned 2 feet, where the good geometer is able to see how many feet, how many bricks, how much sand (*arena*) and burnt lime (*calcina*).

There is no theoretical elaboration of military perspective until Bonaiuto Lorini, who wrote of a “more common perspective,” and how “such perspectives have to show their own height from close-to; thus they are all formed of parallel lines both for the height and for the width of any building whatsoever, though placed perpendicular to its plane…drawing the lines so that they fall perpendicular and remain parallel to infinity.” The succession of treatises that elaborate military perspective – Jacques Androuet du Cerceau, Ambroise Bachot and Jacques Perret – is well documented (Scolari, Galindo Dias).

More interesting is to ask where the conventions were put into practice, either in a manuscript or printed context. To judge where true military perspective is being used, one must find drawings in which there is no diminution and the front and back of a fortress, for example, have curtain walls the same height. Even better, if a scale is attached one has even more of a mandate to extract absolute measures not only from frontally represented elements – the width and height of a façade – but also the depth of the *enceinte*.

By the middle of the sixteenth century, manuscript maps were widely circulated and some published as prints. When wars and other events of note occurred, it was possible for printmakers to obtain plans of high reliability. One such printmaker was Domenico Zanoi, whose plan of Vienna was published during the Habsburg-Ottoman war of 1566. Zenoi consistently follows the rules of military perspective with the curtain wall a ribbon of parallel lines. Furthermore, he includes a dimensional scale of *canne*. The plan is combined with information that can be used approximately with the height of the walls to truly appreciate the characteristics of the city’s defenses.

As engineers, architects and draftsmen became more and more comfortable with military perspective, its potential for rapid visualization was realized. Just as three-dimensional models were derived from plans, the rise of military perspective allowed a kind of model making without the extensive cost of an actual model.

**References:**

Belluzzi, Giovan Battista, *Libro di fortificazioni, assedij et difese di piazze*, c. 1545, Archivio Storico Comunale di Anghiari, F. 1624, in Daniela Lamberini, *Il Sanmarino: Giovan Battista Belluzzi architetto militare e trattatista del Cinquecento*, 2 vols. (Florence: Leo S. Olschki, 2007).

Belluzzi, Giovan Battista, *Nuova inventione di fabricar fortezze* (Venice: Tomaso Baglioni, 1598).

Maggi, Girolamo, and Jacopo Castriotto, *Della Fortificatione della Città … libri tre* (Venice: Rutilio Borgominieri, 1586).

Lorini, Bonaiuto, *Delle fortificationi libri cinque* (Venice: Antonio Rampazzetto, 1596).

Galindo Diaz, Jorge, “The Dissemination of Military Perspective through Fortification Treatises between the Sixteenth and Eighteenth Centuries,” *Nexus Network Journal* 16 (2014): 569-85.

Huppert, Ann, “Practical Mathematics in the Drawings of Baldassarre Peruzzi and Antonio da Sangallo the Younger,” in Anthony Gerbino, ed., *Geometrical Objects: Architectural Practice and the Mathematical Sciences 1400-1800* (Cham: Springer, 2014), 79-106.

McGee, David, “The Origins of Early Modern Machine Design,” in Wolfgang Lefèvre, ed., *Picturing Machines 1400-1700* (Cambridge, MA: MIT Press, 2004), 53-84.

Scolari, Massimo, *Oblique Drawing: A History of Anti-Perspective* (Cambridge, MA: MIT Press, 2012).

**Further reading:**

Filippo Camerota, “Renaissance Descriptive Geometry: The Codification of Drawing Methods,” in Wolfgang Lefèvre, ed., *Picturing Machines, 1400-1700* (Cambridge, MA: MIT Press, 2004), 175-208.