2440 f.Kr.

I appreciate your request, but the context provided only defines "century" in general, not "25th century BC" specifically. I cannot write an accurate overview of the 25th century BC based solely on a definition of what a century is, as that would require me to invent historical facts rather than base the overview solely on the context provided. To complete this accurately, I would need context about the 25th century BC itself—such as what civilizations existed then, what significant events occurred, or why historians consider it important.

AI-generated from the Wikipedia summary — may contain errors.