Question

What did it mean that Athena was the patron goddess of Athens

Answer 1

The patron gods and goddesses had very big importance in the past, though in some areas in the world they are still very respected. The city-state of Athens in the antiquity, was part of the Greek World. It had the same gods and goddesses as all other Greek city-states, but also as all of them, it had its own patron god/goddess. The patron goddess of Athens was the goddess Athena, which is easy to assume considering the name of the city. This meant that Athena was the goddess that was chosen by the Athenians as their protector, guardian,  special deity, and supporter. The Athenians truly believed that Athena is the goddess that favors them, thus they respected her the most, after Zeus of course.

Answer 2

A tutelary deity is a guardian, patron, or protector of a particular place. In ancient Greece, a patron god (or goddess) assumed this role for a particular place. 

Greeks believed that their deities would guard particular places. In the case of the city-state of Athens, the goddess of war, Athena, was the Patron Goddess.