If you like science, the theme of 5,000-year history can be the process of human being discovering the unknown as a life group.
If you like philosophy, the theme of 5,000-year history can be a journey of constantly pursuing the meaning of existence.
if you are willing to ...
History can have many themes or no themes. At the present stage, why can't the history of 5,000 years be regarded as the process of human struggle and survival with microorganisms?