Date of the Codex
The nature of some of the topics covered (such as the project to divert the Arno River) allows us to affirm that Leonardo began writing sector A in the summer of 1503 and that his last notes are not later than mid-1505.
History and journey of the Codices
The Codices were brought to Spain by Pompeo Leoni, sculptor to Philip II. After several changes of ownership, they passed to the Library of the Monastery of El Escorial, finally passing to the Royal Library, where they remained lost for 150 years.
These manuscripts are of great importance in Leonardo's work, as they contain about 15% of Leonardo's notes referenced today, but they are also important for the quality and relevance of the topics they contain, which represent one of the most important engineering treatises of the period.
Upon Leonardo's death, they passed to his friend Francesco Melzi. Some fifty years later, Pompeo Leoni, a sculptor in the service of Philip II, acquired them from his son Orazio and took them with him to Spain.1 Upon Leoni's death in 1608, the manuscripts passed into the hands of Juan de Espina, a friend of Francisco de Quevedo y Villegas, according to contemporary gossip: "a gentleman who lives alone in a mansion in Madrid and whose servants are wooden automata."
The Prince of Wales (Charles), during his visit to Madrid in 1623, became interested in the manuscripts, and Espina freed himself from the obligation by presenting them to the King. The Codices arrived at the Royal Library in 1712, where for various reasons they remained lost until 1967, according to Martín Abad "due to the transfer of the royal library to four different locations, a fatal confusion of call numbers, and the aura of Leonardo da Vinci, which blinded many to link his fame to that of the genius."
A treasure lost 150 years ago
It was a researcher at the University of Massachusetts, an expert in medieval Castilian literature, who discovered them by chance, in 1967, when he came across two codices written by Leonardo Da Vinci in his own handwriting.
They had been lost in the archives of the National Library of Spain. An error by the chief librarian in coding their numbering caused them to be lost for 150 years, until they were discovered by the American Jules Piccus, who was in the Library searching for medieval songbooks.
Bound collections of Leonardo's work, notebooks and loose notes are preserved... the Madrid Codex being a bound collection.
Leonardo's death marked the beginning of the dispersal and loss of two-thirds of the fifty thousand original multidisciplinary documents written in Old Tuscan and codified by him. Every manuscript, page, sketch, drawing, text, and note was fully considered a work of art. Only about thirteen thousand documents remain, most of them preserved in the Vatican City archives.
