1980-Thundarr The Barbarian

The year: 1994. From out of space comes a runaway planet, hurtling between the Earth and the Moon, unleashing cosmic destruction! Man's civilization is cast in ruin!
Two thousand years later, Earth is reborn...A strange new world rises from the old: a world of savagery...super science, and sorcery. But one man bursts his bonds to fight for justice! With his companions Ookla the Mok and Princess Ariel, he pits his strength, his courage, and his fabulous Sunsword against the forces of evil.
He is Thundarr, the Barbarian!
The characters on this show were created by the same guy that created Space Ghost in the 60s. Thundarr the Barbarian was set in 3994 where earth is a post-apocalyptic wasteland where it is ruled by the 7 Citadels of Sorcery, a group of evil sorcerers who use a combination of magic and highly advanced technology to rule over the hapless populace.