which one? (excluding, fire or the wheel or farming) i mean ones you can put a date on, and if you want please, leave a short reason........i say 1450 because of the printing press.

This is going to be hard to judge.

For modern history, I think 1914, 1917 or 1945. If we go further back in history, we would have 1776 (American Independence), 1521 (Martin Luther, Suleiman captures Belgrade, outbreak of the Italian Wars, destruction of the Aztec Empire), 1492 (Columbus' voyage, end of Muslim power in Spain), 1453 (siege of constantinople, end of hundred years war, arrival of printing press in Europe), 636 (Battle of Yarmuk, Battle of Qadisiyya), 622 (the Hegira), 30 (crucifixication of Jesus), etc.

c. 480 BCE - whenver Thermopylae/Marathon/all those battles were - ensured the survival of the West

1421 - lightning bolt hits Chinese imperial palace. Goodbye world domination.

c.1150 BCE - Sea Peoples running around. GOodbye old world order and too bad Egypt, you ain't going to be world power anymore.

The first one.

Ok, you said you want real dates. For the 2nd Millenium, I think 1453 was quite important. 4 very important events (that were going to seriously affect the history of the world) happened in that year.