Helen of Troy became rulers of Sparta, after Tyndareus and Leda abdicated. Menelaus and Helen rule in Sparta for at least ten years; they have a daughter, Hermione, and (according to some myths) three sons: Aethiolas, Maraphius, and Pleisthenes. The marriage of Helen and Menelaus marks the beginning of the end of the age of heroes. Concluding the catalog of Helen's suitors, Hesiod reports Zeus' plan to obliterate the race of men and the heroes in particular. The Trojan War, caused by Helen's elopement with Paris, is going to be his means to this end. Paris, a Trojan prince, came to Sparta to
Menelaus of Alexandria great circle arcs, which he named "trilaterals") and proves Menelaus' theorem on collinearity of points on the edges of a triangle (which may have been previously known) and its analog for spherical triangles. It was later translated by the sixteenth century astronomer and mathematician Francesco Maurolico. The lunar crater Menelaus is named after him. The titles of a few books by Menelaus have been preserved: Menelaus of Alexandria Menelaus of Alexandria (; , "Menelaos ho Alexandreus"; c. 70 – 140 CE) was a Greek mathematician and astronomer, the first to recognize geodesics on a curved surface as natural analogs of