From Pantheon.org's article on him:

"Being the supreme ruler he upheld law, justice and morals, and this made him the spiritual leader of both gods and men.........He brought peace in place of violence and Hesiod (circa 700 BCE) describes Zeus as "the lord of justice". Zeus was also known as "Kosmetas" (orderer), "Soter" (savior), "Polieos" (overseer of the polis, city) and "Eleutherios" (guarantor of political freedoms)." 24.180.173.157