Leonardos Architecture

The construction of the Florence Cathedral, especially the dome designed by Brunelleschi, had a great influence on Leonardo's ideas about architecture. Construction of what was then the largest dome in the world was completed in 1468, the time of Leonardo's apprenticeship with Andrea del Verrocchio. Verrocchio's workshop made the 2m gilded copper sphere that sits atop the dome. Leonardo was also heavily influenced by antiquity. He owned a copy of "Ten Books on Architecture." The textbook of the ancient master builder Vitruvius is the only surviving book on ancient construction. Likewise, Leonardo studied the ancient ruins in northern Italy and especially in Rome, where he visited, for example, Hadrian's Villa near Tivoli. Leonardo's late designs for Chambord Castle also indicate that his reflections on the laws of motion were incorporated into his designs.

Florence at the time of the Renaissance was a commercial and banking metropolis and was one of the richest cities in Europe. The city was also a republic (since 1115), meaning that the government was essentially composed of representatives of the resident guilds and the citizens were free, i.e. serfdom was abolished. The rich families promoted the arts to such an extent that Florence was the cultural capital of Europe at the time. The influential Medici banking family was particularly prominent. The city's self-confidence and wealth are expressed above all in the buildings created at this time, which still characterize the cityscape today. Typical of these buildings are the white marble from the region and geometrically structured facades.

Leonardo moved to Florence from the Florentine suburb of Vinci between the ages of 12 and 16. To understand Leonardo's architectural designs, it is important to know the most culturally significant buildings in the city. The imposing nature of these buildings, as well as their frequent sight, certainly left a strong impression on the young Leonardo. The memory of the architects of these buildings was very present. Thus, Giotto, Brunelleschi and Alberti had an almost legendary status in the city.

A major influence on Renaissance architecture was the book "Ten Books on Architecture" by the ancient master builder Marcus Vitruvius Pollio, known as Vitruvius (1st century BC), who worked for the Roman dictator Caesar and his successor Emperor Augustus. Vitruvius' book is the only work on architecture preserved from antiquity. Vitruvius is best known today for a drawing by Leonardo. The Vitruvian Man illustrates the theory of proportion according to Vitruvius.

Significant for the Renaissance is the fact that Vitruvius stretches the concept of the architect further. In the first chapter (Book 1), he lists the ten educational contents of architects: Literacy, Drawing, Geometry, Arithmetic, History, Philosophy, Music, Medicine, Law and Astronomy. Vitruvius's book further deals with the subjects of water supply, clock-making and mechanical engineering. Therefore, it was natural for architects, both in antiquity and in the Renaissance, to be knowledgeable in all areas of construction: Idea, design, organization and practical execution. This meant that the master builders were responsible, among other things, for the construction of building machines, cranes, machines for working stone and machines for the production of tools.

The Florentine Brunelleschi (1377-1446) was not only a gifted architect and sculptor but also a talented engineer and inventor. He invented a gear system for construction cranes that allowed for the lifting and lowering of baskets through a mechanical switch. Prior to this invention, the mules powering the crane's rotation had to be rehitched in the opposite direction, which was very time-consuming. He also developed a special ferry for transporting heavy marble blocks, although it sank during its first use. Additionally, he excelled as a designer of lifting platforms for theatrical performances.

Brunelleschi was the architect of the central structure with the monumental dome for the Cathedral of Florence. The dome remained the world's largest dome construction until the 19th century and marked the beginning of an era of grand dome buildings, including St. Peter's Basilica in Rome (started in 1506), St. Paul's Cathedral in London (begun in 1710), and the United States Capitol in Washington, D.C. (commenced in 1864), to name just a few.

The Myth of April 15th

It is no coincidence that April 15th marks both the day of Brunelleschi's death (1446) and the birthday of Leonardo da Vinci (1452). Brunelleschi likely passed away at the age of 69, and Leonardo at 67. Despite his prominent significance during his lifetime, Brunelleschi's exact birth and death dates remain uncertain. It is probable that early biographers chose to align Brunelleschi's death with Leonardo's birthdate to emphasize the seamless transition of the tradition of fine arts in the Republic of Florence. While Brunelleschi did not complete his ambitious project to create the world's largest dome for the Florence Cathedral, it is highly likely that the then 16-year-old Leonardo was involved in the final stages of the project. The workshop of his master Verrocchio was tasked in 1468 with installing the approximately two-meter-high gilded copper sphere on the cathedral's dome, and Leonardo, as a student of this workshop, would likely have been involved in these efforts.

Brunelleschi died before Leonardo was born, but Alberti (1404-1472) lived to see Leonardo. Like Brunelleschi, Alberti was not a classical architect, but a universally learned artist: lawyer, writer, author of art theoretical writings, surveyor and mathematician. With regard to Leonardo, it is not insignificant that one of his art-theoretical writings bears the title De pictura ("On the Art of Painting"). In it there are numerous similarities with Leonardo's own work "Trattato della Pittura" ("Treatise on Painting"), for example when he designates nature as the source of inspiration.

Alberti, in contrast to Brunelleschi, was more beautiful and less practically oriented. Thus he contented himself with the design of buildings and left the actual execution to site managers, which was a revolution at the time. He thus emphasized the spiritual character of architecture and transferred its perception away from craft and toward art. This quality of frugality, of enjoying the idea and the design itself without insisting on the inconveniences of practical execution, is a quality that also seems to be inherent in Leonardo.

Presumably, with the youthful Leonardo's move from Vinci to Florence (1464-1468), his apprenticeship under Verrocchio began. The focus of this education was undoubtedly on sculpture and painting, as there is no record of architectural work by Verrocchio. However, as was customary in the artist workshops of that time, the practical aspects of painting and sculpture were only a small part of Leonardo's education. His training was based on the general subjects known from antiquity, following the principles of the "seven liberal arts": grammar, rhetoric, logic, arithmetic, geometry, music, and astronomy.

Whether Leonardo came into contact with Vitruvius' textbook on architecture during his time with Verrocchio is unclear. He later possessed a copy, as evidenced by his book lists. During Leonardo's apprenticeship, Verrocchio's workshop was tasked with installing a 2-meter-tall gilded copper sphere on the dome. The installation of the sphere was meant to mark the completion of the work on Brunelleschi's dome on the Florence Cathedral. It was customary at the time for Verrocchio to create the necessary structures and cranes for such work. It is likely that the then 16-year-old Leonardo was involved in these tasks. It is also possible that through Verrocchio, Leonardo had the opportunity to meet the legendary architect Alberti. Given the significant role of Verrocchio's workshop in Florence, it is probable that they crossed paths there. Alberti passed away when Leonardo was 20 years old.

According to sources, Leonardo first appears as an architect around 1487, when he offers himself in a metaphorical letter as a doctor for the ailing Milan Cathedral, which was still under construction at the time. Leonardo does not receive the commission.

In 1488 Leonardo travels to Pavia, where the construction of a cathedral is begun. At the same time Bramante was also there. The cathedral of Pavia was a monumental project similar to the one in Florence. Even though the diameter of the dome was about 1/4 smaller, it was to be the third largest dome of its time. Whether Leonardo traveled out of curiosity, hoped to be commissioned to supervise construction, or was invited as a consultant is unclear today. Two years later, the construction manager of the Milan Cathedral is invited to Pavia for consultation. In the PS, the invitation is extended to Leonardo as well, who then travels to Pavia to consult with the cathedral building authorities. Bramante is in Pavia at the same time.

Who exactly is responsible for the design of the cathedral in Pavia is unclear. Bramante, Leonardo or Francesco di Giorgio, the director of the Milan cathedral, are all possible candidates. Historians agree that the construction was a pilot project for St. Peter's Basilica in Rome and at the same time references to the sacred buildings in Florence, Leonardo's hometown, can be recognized.

Leonardo's famous painting The Last Supper is also associated with Bramante. The church of Santa Maria delle Grazie in Milan had been completed in 1490, when the Milanese ruler Ludovico Sforza decided to make it the burial place of the Sforzas. Therefore, the eastern part of the building with the altar, which had just been completed, was demolished and replaced by a central building starting in 1492. Bramante supervised the project. While construction was underway on the prestigious project, Leonardo began the Last Supper painting in 1495, which was located in another part of the building. He finished the painting in 1498. With the expulsion of Ludovico Sforza, Bramante and Leonardo left Milan. Both initially wanted to go to Rome together, but they parted ways. Leonardo went back Florence and Bramante began to seek the commission to build St. Peter's Basilica.

The Tempietto (Ital. 'little temple') was Bramante's first commission in Rome.It was a new type of building at that time, the Church of the Holy Sepulchre in central construction. The commission for this inconspicuous work is directly related to the commission for the construction of St. Peter's Basilica. This is because the circular building is located on the assumed site of the crucifixion of the Apostle Peter. St. Peter's Basilica, on the other hand, is located over the assumed tomb of Peter. In this respect, the Tempietto is already a preliminary work for St. Peter's Basilica.

About five years later, an ancient burial mound was discovered in Tuscany, the "Tumulo di Montecalvario", in which Leonardo became interested. He was inspired to design a monumental burial mound, which had little in common with the ancient tomb actually found. Instead, the architectural structure in Leonardo's sketch is reminiscent of Bramante's Tempietto in Rome. Leonardo makes it clear in his drawing that the effect of a building depends not only on its shape, but also on its interaction with its surroundings. In this respect, Leonardo's sketch is certainly a critical view of Bramante's circular building, even though he was undoubtedly inspired by the latter's design.

Donato Bramante is regarded as the architect of St. Peter's Basilica. The construction, which began in 1506, was the costliest and most protracted building project of its time. The taxes, levies, and especially the extensive sale of indulgences used to finance it eventually led many believers to turn away from the Church, ultimately resulting in the Protestant Reformation in 1517.

Was Leonardo the source of inspiration for the design of St. Peter's Basilica?

Leonardo's drawings, especially those found in the Paris Manuscripts, include numerous central-plan designs that strongly resemble the current St. Peter's Basilica. These drawings are dated to 1490, approximately 15 years before the construction of St. Peter's Basilica began. Therefore, it is likely that Leonardo, given his long-standing close collaboration with Bramante, influenced the ideation process. Between 1513 and 1516, Leonardo himself was at the papal court in Rome, where he reencountered Bramante and Raphael. Bramante passed away during this period (1514), after which Raphael oversaw the construction site until 1520. The extent of Leonardo's influence on the construction work is unclear, but his significant influence on Raphael is widely acknowledged. Moreover, his notebooks reveal that he was intensely engaged in experiments related to the effects of forces, which are essential for understanding structural engineering, during this time.

Even though there were various modifications during the over 120-year construction history of St. Peter's Basilica, the structural framework was well-advanced after a few years, making substantial alterations difficult. This means that during this time, the fundamental form of the building was already established. It is crucial to note that Leonardo consistently favored the central-plan design, and Bramante originally intended St. Peter's Basilica as such. However, subsequent architects added a long nave to the design. They also disrupted the original symmetry of the central structure by placing only two corner towers on the roof instead of the originally planned four. The foundations for the two missing towers on the roof are still clearly visible from the air. Despite the later modifications to the original plan, the interior of the building has retained the character of a central-plan structure with an impressive dome. The diameter of St. Peter's Basilica's dome is approximately 1 meter smaller (about 42 meters) than that of the Florence Cathedral (about 43 meters). It was not St. Peter's Basilica but the Florence Cathedral that held the world's largest dome for over 400 years.

The basic idea of St. Peter's Basilica was a central building that would unite the basic forms of geometry. In an imaginary cube there is a building striving upwards. Up to half the height, the cube is a cuboid building. Four smaller towers, placed at the corners but moved inwards, were placed on the roof. In the middle of the roof a cylinder leads upwards, on which a hemispherical dome is placed. A pyramid-like silhouette is formed in the upper half of the imaginary cube. St. Peter's Basilica thus combines the classic basic bodies of geometry: cube, cylinder, sphere and pyramid. This elementary reduction is typical for the Renaissance and especially for Leonardo.

The painting is located in the former private chambers of the popes in Rome (Stanzas of Raphael). It is striking that Raphael painted three artists in the picture, who were subsequently to oversee the construction of St. Peter's Basilica. Leonardo, Bramante, Raphael and Michelangelo are the only famous contemporary figures in the painting. Raphael, for example, does not show Botticelli, who was still alive in 1510 and painted parts of the Sistine Chapel alongside Michelangelo, so he was also a very famous artist.

Bramante, the original architect draws as Euclid with a compass on a chalkboard. After his death in 1514, Raphael took over the site, but died very young in 1520. Finally, Michelangelo took over the site in 1547 until he died in 1564.

Leonardo da Vinci, as Plato, is one of the two central figures in the center of the painting. Plato's student Aristotle is walking next to him. He cannot be assigned to any contemporary person. Plato is carrying his book Timaeus, known for the first mention of the legend of Atlantis, but especially for the geometrical treatise on the five Platonic solids (cube, tetrahedron, etc.). Michelangelo leans on a stone cube that forms the central basic shape of St. Peter's Basilica. Plato points symbolically upwards. Does he mean the not yet existing dome?

Leonardo's city plan of Imola is considered the oldest surviving city plan of the modern era that aims to accurately depict a city's street layout to scale. Even the contemporary architect Leon Battista Alberti, whom the young Leonardo likely knew, created a city plan, although he did not use an odometer. Alberti's plan is not nearly as detailed as Leonardo's city plan of Imola.

Leonardo spent the winter of 1502/1503 in Imola while accompanying Duke Cesare Borgia, the son of the Pope and commander of the papal army, on his military campaigns through central Italy. Cesare Borgia established his winter quarters in the city and held court there.

To precisely measure the streets of Imola, Leonardo constructed an odometer (from the ancient Greek "hodómetron," meaning "way measurer"). This is a mechanical device on wheels that measures a traveled distance through a system of interlocking gears. Leonardo did not invent the odometer. The ancient architect Vitruvius provides a detailed description of such a device in his "Ten Books on Architecture" (Book 10, Chapter 9). It is likely that the odometer was already in use in ancient Rome, as surviving plans from that time are remarkably accurate (e.g., the "Forma Urbis Romae" from around 200 AD). Knowledge of surveying with an odometer was temporarily lost with the collapse of Roman culture and was rediscovered during the Renaissance.

Leonardo possessed a comprehensive understanding of physics, including the derivation of forces. This made it relatively easy for him to develop entirely novel types of bridges. Leonardo was in search of practical bridge designs, as evident in his design for a revolving bridge. The idea was entirely innovative and could only be conceived through the fusion of knowledge in mechanical engineering and architecture, a characteristic of the Renaissance era. The bridge was practical in that it didn't obstruct maritime traffic. If large ships approached, the bridge could be rotated toward the shore. Similarly, it could be rotated during sudden floods, as these often carried logs and debris that could severely damage bridges.

Leonardo's Bridge for Cesare Borgia

Leonardo designed a bridge for the first time, consisting of simply stacked wooden elements without the need for ropes, nails, or similar connections. Such a bridge was highly practical for military campaigns, as it could be quickly assembled and disassembled without additional materials. Leonardo constructed this bridge around 1502/1503 while accompanying Cesare Borgia ("il Valentino") for several months on a military campaign through central Italy. Cesare was the son of Pope Alexander VI and the commander of the papal army. The mathematician Luca Pacioli (1445-1517), who collaborated closely with Leonardo, reported this in his book "De viribus quantitatis" (1508):

"One day Cesare Valentino, Duke of Romagna and Lord of Piombino, with his troops stood at a river that was 24 paces wide and found no bridge and no building material from which he could have constructed one, except for a pile of wood cut to a length of 16 paces. From this wood, his noble engineer built a bridge without iron, rope, or any other material, and it was so strong that the army could cross the river on it."

Pacioli likely rounded the measurements, but the bridge was probably over 10 meters long in this manner. Leonardo's bridge is now a popular wooden toy for children and is demonstrated in playful experiments at universities, among other places.

The Ottoman Empire had conquered Constantinople, now Istanbul, in 1453. Fifty years later, Sultan Bayezid II planned a massive bridge to connect the historic city center with the northern neighborhoods, separated by the approximately 250-meter-wide inlet known as the Golden Horn. An excerpt of a letter that Leonardo is said to have sent to the Sultan of the Ottoman Empire is preserved in the Topkapi Museum in Istanbul. Leonardo's letter is dated to the summer of 1503, placing it in the same timeframe as the bridge for Cesare Borgia:

"I, your servant, have heard that you intend to build a bridge from Istanbul to Galata and have not done so because you have found no one capable of the task. I, your servant, know how it can be done. I would build it as high as a building, so that no one could cross it because it is so high... I would construct it so that ships could pass beneath it even with all sails set... I would build a drawbridge so that you can reach the Anatolian coast if you wish. May God grant that you believe my words, believe my words, and see in me your servant who is always at your service."

In one of his notebooks, Leonardo made a drawing of this proposed bridge and added some measurements: "Bridge from Pera in Constantinople. 40 ells wide, 70 ells high above the water, 600 ells long, namely 400 over the sea and 200 on land, where it is supported." One ell was approximately half a meter. Thus, the bridge was to have a length of 300 meters, making it the largest bridge in the world at that time. There is no known response from the Sultan to Leonardo's letter, and there is no evidence of Leonardo's presence in Istanbul.

Michelangelo's Bridge for the Sultan

It is noteworthy that Michelangelo, the famous sculptor and later architect of the St. Peter's Basilica in Rome, is said to have also considered building a bridge over the Golden Horn around the same time as Leonardo. Leonardo and Michelangelo were in Florence at this time, both working on separate, unfinished paintings for the same hall (Leonardo's "Battle of Anghiari" and Michelangelo's "Battle of Cascina"). The renowned biographer Vasari mentions this in his 1550 biography of Michelangelo:

"While Michelangelo was in Florence, he was careful to complete the cartoon for the great hall within the three months of his stay there. During this time, the Signoria received three breves demanding that Michelangelo be sent back to Rome. From this, he perceived the Pope's anger, and since he mistrusted his own safety, he even entertained the idea of going to Constantinople to serve the Grand Sultan, who had expressed a desire for him through the mediation of some Franciscan monks, to build a bridge from Constantinople to Pera. But Soderini persuaded him, albeit reluctantly, to visit the Pope, and for his protection, he went into public service as an envoy of the city."

Designing an ideal city was a typical thought process of Renaissance architects. In drawing up such a plan, so many things had to be considered that the mind was trained universally, just as the ancient model Vitruvius had understood architecture. Important topics were the arrangement of living areas, public squares and recreational facilities, the distribution of infrastructure buildings, water pipes, defense facilities and much more.

Leonardo stayed in the Duchy of Milan between 1482 and 1499, and from about 1487 he was a member of the Milanese court. The city was already at that time a metropolis and belonged with approximately 100,000 inhabitants to the five largest cities in Europe. Due to the dense construction and the hygienic deplorable conditions typical of the Middle Ages, rats were omnipresent. In 1485 there was a devastating plague epidemic with many deaths. Under this impression, Leonardo began his own reflections on an ideal city. His main concern was to structure the city vertically and to make it cleaner by means of an adequate sewerage system and a waste collection system.