The bound notebooks
The great codices are the bound notebooks in which Leonardo set down a lifetime of inquiry — art, anatomy, mechanics, water, flight and the heavens — often writing in mirror script from right to left. Scattered after his death, they survive today across libraries in Milan, London, Madrid, the Vatican, Turin and a private vault in Seattle.
Codice Atlantico
The largest single collection of Leonardo's papers — 1,119 leaves spanning 1478–1519. A vast compendium of mechanics, mathematics, astronomy, botany, flight, weaponry and architecture, assembled by the sculptor Pompeo Leoni and held at the Biblioteca Ambrosiana in Milan.
Codice Arundel
A bound miscellany of some 280 leaves gathered after Leonardo's death, ranging from c.1480 to 1518. Rich in physics, geometry, optics and the behaviour of water; named for the Earl of Arundel and now in the British Library.
Codice Forster I
A pocket notebook (Victoria & Albert Museum) on hydraulic machines and the measurement of solids — Leonardo's studies of moving earth and water, with geometry, from the early 1490s.
Codice Forster II
Two small notebooks bound together (V&A) on the theory of proportion, light and shade, and weights — reflections from Leonardo's years in Milan.
Codice Forster III
A pocket notebook (V&A) of miscellaneous notes from Milan around 1490–93 — anatomy, hydraulics, architecture, costume and aphorisms jotted on the move.
Codice di Madrid I
Rediscovered in Madrid in 1965, a treatise on theoretical and applied mechanics — gears, springs, clocks and machine elements — among the finest of all Renaissance engineering manuscripts (Biblioteca Nacional de España).
Codice di Madrid II
The companion Madrid codex: geometry, the casting of the colossal Sforza equestrian monument, fortification and cartography, including Leonardo's survey of the Arno valley (Biblioteca Nacional de España).
Codice Urbinate lat. 1270
The Codex Urbinas — Leonardo's thoughts on painting, compiled posthumously by his pupil Francesco Melzi into the celebrated Trattato della pittura, the foundation of his artistic theory (Vatican Library).
Codice Leicester
A focused study of water, rock and the cosmos written c.1508–10 — including Leonardo's explanation of the pale light of the moon. The only codex in private hands, owned by Bill Gates.
Codice Trivulziano
An early notebook (c.1487–90) filled with the Latin vocabulary lists Leonardo set himself to learn, alongside studies of architecture and ecclesiastical buildings (Castello Sforzesco, Milan).
Codice sul volo degli uccelli
A small 1505 codex devoted to the flight of birds and the design of a flying machine — Leonardo's analysis of wings, air and balance (Biblioteca Reale, Turin).