The armillary sphere is a demonstrational model of the universe. Composed of several rings (Armillae in Latin) and a band for the Zodiac, it represents the apparent movement of the celestial sphere around the Earth and marks the Sun's annual progress around the ecliptic.
Their use can be traced back to antiquity and the handful of earliest extant examples date from the Middle Ages. But it was in the 16th and 17th centuries that their construction reached a peak and they became such iconic instruments of science. Elaborate and decorative examples were made for princely collections and they became symbolic of astronomy in paintings and engravings of the time.