The Ptolemaic Kingdom of Egypt was a Hellenistic kingdom that existed from 305 BC to 30 BC, following the death of Alexander the Great. It was founded by Ptolemy I Soter, one of Alexander's generals, who became the first ruler of the dynasty. The kingdom is known for its rich cultural blend of Greek and Egyptian traditions, as well as its significant contributions to art, science, and philosophy. The capital city, Alexandria, became a major center of learning and commerce, housing the famous Library of Alexandria. The Ptolemaic dynasty ended with the reign of Cleopatra VII, whose alliances and conflicts with Rome ultimately led to the kingdom's downfall and the annexation of Egypt by the Roman Empire.