Euclid They follow the same logical structure as "Elements", with definitions and proved propositions. Other works are credibly attributed to Euclid, but have been lost. The European Space Agency's (ESA) Euclid spacecraft was named in his honor. Euclid Euclid (; – "Eukleídēs", ; fl. 300 BC), sometimes given the name Euclid of Alexandria to distinguish him from Euclides of Megara, was a Greek mathematician, often referred to as the "founder of geometry" or the "father of geometry". He was active in Alexandria during the reign of Ptolemy I (323–283 BC). His "Elements" is one of the most influential works in the
Reign of Cleopatra could be classified as Greeks if they abandoned their original cultures, received a Greek education, labeled their gods and goddesses with Greek names, and embraced the Greek lifestyle. Native Egyptians had been largely excluded from serving in the military by the reign of Ptolemy II, replaced by Greek and Jewish landholders called cleruchs. By the reign of Ptolemy IV in the late 3rd century BC they were reintroduced as phalangite soldiers. Large migrations of Greeks to Egypt ceased by the 2nd century BC, so that the Greek minority in Ptolemaic Egypt remained demographically small. Although Egyptian priests were often wealthy