Which king is known for establishing social class based on wealth?

The correct answer is Servius Tullius. He is known for implementing significant social reforms, including the establishment of a class system based on wealth, which was a crucial development in ancient Roman society. This system divided citizens into different classes depending on their property and wealth, thereby influencing their political rights and obligations.

Servius Tullius also introduced the census as a means to assess the wealth of citizens, allowing for more organized recruitment into the army based on property. This class structure became foundational for later political organization in Rome, as it established a linkage between social standing and participation in governance.

In contrast, Augustus is known primarily for his role in the transformation of the Roman Republic into the Roman Empire and his various reforms, but he did not establish the class system based on wealth. Numa Pompilius is celebrated for his religious and legal reforms, and Lucius Tarquinius Superbus is associated with the last king's tyranny, which led to the abolition of the monarchy rather than the establishment of a class system based on wealth.