Recto: The fetus in the womb. Verso: Notes on reproduction, with sketches of a fetus in utero, etc. (c.1511) by Leonardo da VinciRoyal Collection Trust, UK
During the 1480s Leonardo had begun to develop a treatise on painting, which was to cover the theoretical knowledge on the appearance of the natural world that a painter should master. In time this led Leonardo into separate fields of scientific investigation, including anatomy.
Recto: The viscera of a horse. Verso: The hemisection of a man and woman in the act of coition (c.1490-92) by Leonardo da VinciRoyal Collection Trust, UK
Many of Leonardo’s early anatomical drawings were based on a blend of received wisdom, animal dissection and mere speculation. A striking example is his drawing of a hemisected man and woman in the act of coition of around 1490. The diagram demonstrates the belief that conception involved both material and spiritual elements.
The anatomy of a bear's foot (c.1488-90) by Leonardo da VinciRoyal Collection Trust, UK
Although Leonardo had no access to human dissections in the early years of his career, he was able to dissect animals. His drawings of dissections of the foot of a bear – the only large quadruped that walks on the soles of its feet, like man – are among the most impressive of Leonardo’s early studies. Twenty years later, when he found the same structure in the hands and feet of man, he recalled his studies of the bear.
Recto: The skull sectioned. Verso: The cranium (1489/1489) by Leonardo da VinciRoyal Collection Trust, UK
Leonardo’s other early opportunity to investigate the internal anatomy of man came when, in 1489, he obtained a human skull. He sawed it in different sections to study the relationship between its internal and external forms. He used this knowledge of the nerve pathways to the brain to speculate on perception.
R: The viscera of a horse (c. 1490-92) by Leonardo da VinciRoyal Collection Trust, UK
Leonardo’s anatomical interests were reflected in his two principal artistic projects of the 1490s. The mural of the 'Last Supper' was a ground-breaking exploration of the effect of the emotions on the form of man, his attitudes and expressions. A commission to model and cast a huge equestrian monument to Francesco Sforza, father of Ludovico Sforza, then ruler of Milan, led Leonardo to investigate the anatomy of the horse.
A drawing of the viscera of a large quadruped, probably a horse, survives from this period, suggesting that Leonardo conducted full dissections to investigate the internal anatomy of the beast.
A standing male nude (c.1504-6) by Leonardo da VinciRoyal Collection Trust, UK
In 1503 Leonardo received a commission to paint a huge mural of the Battle of Anghiari. This was the most dynamic composition he had ever worked on, involving a wild struggle of man and horse.
Leonardo returned to the study of human and equine anatomy after a gap of more than ten years. He was interested in the superficial musculature of man and the horse galloping, rearing and bucking.
Recto: The vessels and nerves of the neck. Verso: The vessels of the liver (c.1508) by Leonardo da VinciRoyal Collection Trust, UK
Leonardo’s scientific studies throughout his life were characterised by an urge to go ever deeper, to discover fundamental causes, and he was soon drawn back to the study of human anatomy, independently of the specific requirements of the Battle of Anghiari. From this period onwards Leonardo seems to have regular access to human material for dissection.
The subjects of human dissections at this time were usually executed criminals or those who had died with no-one to claim their bodies for burial. The apparent ease with which Leonardo obtained permission to perform the dissections suggests that he now had some reputation as an anatomist.
R: Muscles of the shoulder and arm. V: Muscles of the shoulder and arm, and the bones of the foot (c.1510-11) by Leonardo da VinciRoyal Collection Trust, UK
In the winter of 1510-11 Leonardo was working in the medical school of the University of Pavia alongside the professor of anatomy Marcantonio della Torre. He may have dissected up to 20 human bodies at that time and he recorded his findings on 18 sheets known as the Anatomical Manuscript A. Bones and muscles were now the focus of Leonardo’s investigations, rather than internal organs.
R: The heart, bronchi and bronchial vessels by Leonardo da VinciRoyal Collection Trust, UK
With a skilled engraver, the drawings of the Anatomical Manuscript A would have served magnificently as illustrations to the treatise on anatomy that Leonardo intended to publish. However, in 1511 Marcantonio della Torre died of the plague. As a result Leonardo lost his ready access to human material and his anatomical interests soon reverted to detailed studies of specific topics based largely on animal dissection.
At Leonardo’s death in 1519 his anatomical drawings remained among his private papers; they were essentially lost to the world, and it was not until the modern era that they were fully published and understood.