Foundations of geometry possible exception of the parallel postulate) that any theorem proved from them was deemed true in an absolute, often metaphysical, sense. Today, however, many other geometries which are not Euclidean are known, the first ones having been discovered in the early 19th century. Euclid's "Elements" is a mathematical and geometric treatise consisting of 13 books written by the ancient Greek mathematician Euclid in Alexandria c. 300 BC. It is a collection of definitions, postulates (axioms), propositions (theorems and constructions), and mathematical proofs of the propositions. The thirteen books cover Euclidean geometry and the ancient Greek version of elementary number theory.
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