The Codex Atlanticus (1478-1518) is the largest collection of drawings and writings by Leonardo da Vinci (1452-1519). The artist's myriad interests are reflected in the books' contents: anatomy, astronomy, aviation, botany, chemistry, complex mathematics, geography, industrial engineering, mechanics, musical instruments and weaponry. Its atlas-like dimensions (61 x 44 cm) give the compendium its name.

Painting, architecture and sculpture are also treated in the codex's pages. Included are Leonardo's pen and ink studies for his unfinished Adoration of the Magi altarpiece (ca. 1479-81), the Duomo di Milano (Milan Cathedral) and his unrealized equestrian monument to Francesco Sforza (1401-1466), a condottiere or hired mercenary.

The manuscript's miscellaneous musings and drawings were organized by Italian Mannerist sculptor and medallist Pompeo Leoni (1533-1608) in the late 16th Century. In the process, some of Leonardo's precious notebooks were dismembered. The codex's 1119 paper fragments were assembled onto 402 pages and bound into one huge volume.