The Astrolabe was developed at the Greek school in Alexandria about 160 B.C. by Hipparchus. Great scientific strides forward at that time were the result of combining the Greek sciences with Babylonian mathematics. This was all made possible by the conquests of Alexander the Great who established a vast empire throughout the Mediterranean. The Astrolabe was known to scholars from then on, and was used as a slide rule of the Heavens. Direction, time, angles, and the position of the celestial bodies could all be calculated.

When Prince Henry the Navigator established his seafaring fleet, he began using the Astrolabe to navigate the ships. For many years, this gave the Portuguese the exclusive ability to navigate open waters, which the other countries could not do. When Sir Francis Drake raided ports along the South American coast he was forced to flee from the Spanish ships. Drake attacked a Portuguese ship and took its Navigator hostage to guide him on his round the world voyage, thus avoiding the Spanish Fleet. All the great voyagers in the age of exploration navigated with the Astrolabe, including Columbus, Magellan, and Drake.

About 1391 Chaucer wrote his Treatise on the Astrolabe for his son. All scientific texts were written in Latin, so that scholars everywhere could read them. But Chaucer's son was too young at 10 to read Latin, so Chaucer's instructions to his son became the first scientific text written in English.

This Astrolabe is 4" in diameter, 24k gold plated and comes with storage box and Book of Instruction by Chaucer.