Military Power

Best empires that ever rose to power and eventually waned in the claws of history. they are a lot of them for many different reasons but which of them are the best or could have combined assets to form the "ideal" empire?

Standards:
1. citizens freedom/domestic security and well-being
2. economic might
3. military prowess
4. scientific-artistic contribution to humanity

list
1. Roman empire (hyper power status)
2. Persian empire (fluctuating status)
3. Greek-Alexander empire (short-lived)
4. Ottoman empire
5. Mongolian empire

post-roman period:
6. Russian empire
7. French empire (napoleon)
8. Spanish-Portuguese empire
9. Dutch-German empire
Modern versions:
Pax Britannica
Pax estados unidos (US)

chose carefully and why? Not a complete list by any means so if one isn't there I am sorry. Feel free to mention them.