A manuscript illustration of Alexander the Great in a glass diving bell. Alexander III of Macedon (356-323 BC), commonly known as Alexander the Great, was a Greek king who conquered the Persian Empire. The diving bell was first described by Aristotle, who was Alexander's tutor, in the 4th century BC. Alexander's descent in this bathysphere was invented by later medieval historians, and many stories were told about it. In this version, Alexander is accompanied in his underwater exploration by a dog, a cat, and a rooster. He entrusts his most reliable mistress with looking after the chain that pulls the bell up to the surface, but she is persuaded to elope with another man. She throws the chain into the sea, leaving Alexander to figure out his own way up. This miniature illustrates Jansen Enikel's contribution to the World Chronicle, from about 1400-1410, with additions in 1487. Created in Regensburg, Bavaria, Germany. Tempera colors, gold, silver paint, and ink on parchment.