The Ptolemaic Kingdom was a Hellenistic kingdom based in Egypt, ruled by the Ptolemaic dynasty from 305 BC to 30 BC. Its capital was ALEXANDRIA, a major city in Egypt located on the Mediterranean Sea. ALEXANDRIA was founded by Alexander the Great in 331 BC and was the capital of the Ptolemaic Kingdom for nearly three centuries. It was an important center of trade and culture, and was home to the famous Library of ALEXANDRIA.