Zombies go way, way back. The dead in Homer's underworld are basically zombies: shambling and mindless, unless they get some blood to drink. There's the whole Caribbean zombie tradition, of course (White Zombie is pretty dated, but kinda worth seeing), and there's Lovecraft's "Herbert West, Reanimator". But the modern zombie canon (and the idea of zombiedom as an infection, etc.) pretty much starts with Romero, and I guess that's what you're thinking of, Zathras.