Question

What are large, complex, multifaceted, multiethnic, geographically

diverse, populous political entities that often began as "conquest states."

Answer 1

The term you may be looking for is "empires." Empires are large, complex, multifaceted, multiethnic, geographically diverse, and populous political entities that often began as "conquest states." Some examples of empires throughout history include the Roman Empire, the Mongol Empire, the British Empire, and the Ottoman Empire.