Euclid's Elements Euclid's Elements The Elements ( "Stoicheia") is a mathematical treatise consisting of 13 books attributed to the ancient Greek mathematician Euclid in Alexandria, Ptolemaic Egypt c. 300 BC. It is a collection of definitions, postulates, propositions (theorems and constructions), and mathematical proofs of the propositions. The books cover plane and solid Euclidean geometry, elementary number theory, and incommensurable lines. "Elements" is the oldest extant large-scale deductive treatment of mathematics. It has proven instrumental in the development of logic and modern science, and its logical rigor was not surpassed until the 19th century. Euclid's "Elements" has been referred to as the
Ptolemy II Philadelphus and dissolute, intellectual and artificial, has been compared with the Palace of Versailles of Louis XIV of France. Ptolemy deified his parents and his sister-wife after their deaths. Ptolemy II began his reign as co-regent with his father, Ptolemy Soter, from c. 285 to c. 283 BCE, and maintained a splendid court in Alexandria. Egypt was involved in several wars during his reign. His maternal half-brother Magas had declared himself king of Cyrene in 276 and began a war against Ptolemy's government in 274 BCE. Magas managed to keep Cyrenaica independent of the Ptolemies until his death in 250 BCE.