400BC

The year 400 BC falls within the 5th century BC, a period of significant cultural and political development in various parts of the ancient world. In Greece, this year was part of the ongoing Peloponnesian War, though by this point, the major conflict between Athens and Sparta had largely concluded with Spartan victory. However, internal power struggles and smaller conflicts continued to shape the Hellenic world. Philosophical thought was flourishing, with figures like Socrates having recently died and Plato continuing his intellectual work, laying the foundations for Western philosophy.

In the Persian Empire, the Achaemenid Empire was a dominant force. The events of the Anabasis, the march of the Ten Thousand Greek mercenaries through Persian territory, occurred in the years immediately preceding and following 400 BC, highlighting both the reach and the internal weaknesses of the empire. This period also saw advancements in various fields. In medicine, figures like Hippocrates were establishing more systematic approaches to diagnosis and treatment. Astronomical observations and mathematical studies were being pursued, particularly in Babylonia and Greece, contributing to the development of early scientific understanding. The art and architecture of the classical period in Greece continued to evolve, with ongoing construction and artistic creation in major city-states.