400 B.C.E.

* Base-60 astronomy flourishes after Chaldaeans invent " symbol for zero
* Achaemenid Empire of Persia at its greatest; Aramaic becomes the lingua
  franca of the Near & Middle East and its script is adopted farther east
* Kalashoka convenes Second Buddhist Council and issues edicts of Piety &
  Toleration to promote "compassion, liberality, truth, purity, gentleness 
  & saintliness" and encourages vegetarianism
* Parsee Era begins, using the Egyptian civil calendar for months (389)
* Sacrifices to Aphrodite Anahiti, Goddess of Heaven, established by
  Artaxerxes II who invokes her with Ahura Mazda in a trinity with Mithra
  [Herodotus]
* Chinese astronomer Gan De detects Ganymede(+) with the naked eye (364)

* Chaldaean astronomer Kidinnu (Cidenas) accurately describes precession 
  of the lunar orbit, and calculates tropical year to within 5 minutes
* Timoleon's convoy from Corinth to Sicily has a heavenly guide that "came
  to his venture's support, and foretold his coming fame and the glory of
  his achievements, for all through the night was he preceded by a torch    
  blazing in the sky up to when the squadron made harbour in Italy." (343)
  [Diodorus, Library of History, Book XVI, 24-5.]
* Darius III orders that all of the Avesta and the Zend be put in writing,
  one copy for the National Archives, a second for the Royal Treasury
  [The Denkart.]
* Carthage is the leading maritime power: turns Alexander's sights towards
  softer targets in the East; brings goods & their names to America from
  India via 'new' Red Sea canal that extends Spice Route, & vice versa
  <http://en.wikipedia.org/wiki/Special:Contributions/Maizeresearcher>;
* Alexander the Great liberates Egypt from Persian yoke; is declared pharao,
  "son of Amun and saviour" by high priest of Memphis, thereby initiating
  Hellenism as an ideology in which a Hellenic elite is the master race;
  selects as his capital of Egypt a site next to Canopus, named after the
  navigator of Menelaus whose fleet made landfall at the NW corner of the
  Nile's delta, where Kanopos died & was honored by a monument raised by
  his grateful king (thereby the deriviation of eponymous site & star)
  [Homer; Syclax]
* Alexander greatly expands into SW Asia, enabling, despite killing many
  Magoi & Chaldaeans (Cidenas etc.), its cultural influence to flow farther
  west (e.g. philosophy, astrology & associated theories of numbers)
  by sending one copy of Avesta & Zend back to Greece, while destroying
  the other; after his death, Seleucus Nicator founds the Seleucid empire,
  & Era of Alexander begins (as of Treaty of Trisparadisus, 321)
  [Latourette, A History of the Expansion of Christianity. v.I, p.22]
* Aristarchus of Samos born; later teaches that the earth: revolves around
  the sun (as a star at the centre of the universe) in a circular orbit
  small enough to make stellar parallaxes undetectable; is a sphere, whose
  rotation about its polar axis makes it seem as if there were a celestial
  sphere rotating instead (320)
  [Aristarchus, Sizes and Distances of the Sun and the Moon (in which he 
   tells how to measure their relative distances using a geometric method
   that is accurate in theory, but not in practice at the time).]
* Lodestone compass, and Newton's Law of Inertia appear in China;
  [as well as the first reference to the use of a crossbow:
   Sun-tzu, The Art of War. "Use of Energy"]
* Stirrups and paper made in China first
* Buddhism begins to spread beyond southern India
* Emerging artists along the Silk Road in Gandhara start a new art style--
  Serindian (later adapted by missionaries to explain Buddhism)
* Chaldaean astronomer Berossos invents hemicyclia & hemispheria sundials
* In treaty with Chandragupta (founder of the Gupta dynasty), Seleucus I
  yields the upper Indus, Gandhara & Arachosia to the Gupta Empire (305)
  [Mazumdar, Ancient India. p.135]
   300 B.C.E.