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
Cosmas I of Alexandria Cosmas I of Alexandria Cosmas I or Kosmas I () served as Greek Patriarch of Alexandria between ca. 727 and his death in 768. Cosmas was the first residential Chalcedonian (Melkite) patriarch to be established in Alexandria following the Muslim conquest of Egypt in the 640s. The see had remained vacant since, but Cosmas was appointed with the consent of both the Umayyad Caliph and the Byzantine Emperor. The chronicler Theophanes the Confessor reports that in 742/3, he abjured Monotheletism, the dominant doctrine among Alexandrian Melkites since it had been promulgated by Emperor Heraclius. As Cosmas himself was most likely