Non-Euclidean geometry that are both perpendicular to a third line: Euclidean geometry, named after the Greek mathematician Euclid, includes some of the oldest known mathematics, and geometries that deviated from this were not widely accepted as legitimate until the 19th century. The debate that eventually led to the discovery of the non-Euclidean geometries began almost as soon as Euclid's work "Elements" was written. In the "Elements", Euclid began with a limited number of assumptions (23 definitions, five common notions, and five postulates) and sought to prove all the other results (propositions) in the work. The most notorious of the postulates is often
Ptolemaic cult of Alexander the Great propaganda to support the claims of his own dynasty. As part of this effort, Alexander was elevated from a simple patron god of Alexandria to the status of a state god for the Greek populations of the entire Ptolemaic empire, even beyond the confines of Egypt. During the early Ptolemaic dynasty (), Ptolemy I began the construction of the Tomb of Alexander the Great in Alexandria (the , "sēma", ), and appointed a priest (, "hiereus") to conduct religious rites there. This office quickly advanced to become the highest priesthood in the Ptolemaic Kingdom, its prominence underscored by its eponymous