The term "Ptolemaic" refers to the ancient Greek dynasty founded by Ptolemy I, a general under Alexander the Great. This dynasty ruled Egypt from 305 BCE until the Roman conquest in 30 BCE. The Ptolemaic period is known for its blend of Greek and Egyptian cultures, particularly in art, religion, and governance. In astronomy, "Ptolemaic" describes the geocentric model proposed by Claudius Ptolemy, which posited that the Earth is at the center of the universe, with the sun, moon, and planets orbiting around it. This model dominated Western astronomical thought until the Copernican revolution in the 16th century.