Eudoxus of Cyzicus ( ; ; ) was a Greek navigator and diplomat who explored the Arabian Sea for Ptolemy VIII, king of the Hellenistic Ptolemaic dynasty in Egypt.
Voyages to India
thumb|318px|The [[Silk Road extending from southern Europe through Arabia, Somalia, Egypt, Persia, India and Java until it reaches China.]]
According to Poseidonius, later reported in Strabo's Geography, the monsoon wind system of the Indian Ocean was first sailed by Eudoxus of Cyzicus in 118 or 116 BC. Poseidonius said a shipwrecked sailor from India had been rescued in the Red Sea and taken to Ptolemy VIII in Alexandria. The unnamed Indian offered to guide Greek navigators to India. Egyptian ships had traditionally traveled to India by hugging the coast of the Arabian Peninsula, where ships were subject to tolls and pirating, so a separate route that crossed the sea appealed to Ptolemy VIII. Heralds for these festivals were usually elected by fellow citizens, suggesting that Eudoxus was well known and respected in Cyzicus. Eudoxus was reportedly very interested in geography and expressed desire to sail up the Nile. Eudoxus of Cyzicus made two voyages from Egypt to India. The first, in 118 BC, was guided by the Indian sailor. Eudoxus returned with a cargo of aromatics and precious stones, which was all seized by Ptolemy VIII.
It is often suggested that Eudoxus of Cyzicus believed the circumnavigation of Africa was possible because of the proposed theories of Eratosthenes of Cyrene.
It is, however, most likely that Eudoxus never succeeded in circumnavigating the African continent.