The Codex Leicester is a collection of writings by Leonardo da Vinci.

This remarkable 72-page manuscript is almost 500 years old and was handwritten in Italian by da Vinci in his characteristic ‘mirror writing’ and supported by copious sketches. It covers a wide range of his observations and theories on astronomy, the properties of water, rocks and fossils, air and celestial light.

The Codex Leicester provides a rare insight into the inquiring mind of the definitive Renaissance artist, scientist and thinker as well as an exceptional illustration of the link between art and science and the creativity of the scientific process.

The Codex Leicester is owned by Bill and Melinda Gates. As of 2003 it was on display at the Seattle Art Museum.