Ptolemy I Soter way to master it. According to Proclus Euclid famously quipped: "Sire, there is no Royal Road to geometry." Ptolemy I Soter Ptolemy I Soter (; , "Ptolemaĩos Sōtḗr" "Ptolemy the Savior"; c. 367 BC – January 282 BC) was a companion and historian of Alexander the Great who succeeded to his empire. Ptolemy became ruler of Egypt (323–282 BC) and founded the Ptolemaic dynasty which ruled it for the next three centuries, turning Egypt into a Hellenistic kingdom and Alexandria into a center of Greek culture. Ptolemy was the son of Arsinoe of Macedon by either her husband Lagus or
Ptolemy II of Telmessos a paternal first cousin called Antipater Epigonos and likely he had a paternal second cousin called Epigonos. Through his father, Ptolemy II was a direct descendant of Lysimachus who was one of the Diadochi of the Greek King Alexander the Great who was King of Thrace, Asia Minor and Macedonia and Ptolemy I Soter another of the Diadochi of the Greek King Alexander the Great who was the founder of the Ptolemaic dynasty of Ancient Egypt and his wife, Berenice I of Egypt. Berenice I was the great-niece of the powerful Regent Antipater, through her maternal grandfather Cassander, the brother