In hindsight, it's interesting to see zombie movies that were released before "Night of the Living Dead." It was still a time of firsts-"Zombies of Mora-Tau" gave the world the first aquatic zombie flick, "Zombies on Broadway" gave the world it's first "zombedy", and racist bullshit like "King of the Zombies" ended up being largely forgotten for good reason. However, there were some strong titles in this era-Jacques Tourneur gave the world the brilliant "I Walked With a Zombie", and then there's Hammer Films' entry, the 1966 film "I Walked With a Zombie."
When young workers are dying in a mysterious epidemic in ye old Cornwell, Sir James Forbes (Andre Morell, who played Watson in "The Hound of Baskersvilles) goes on to investigate. It turns out that the dead are coming back to life thanks to Squire Hamilton (John Carson), who has been using voodoo to bring them back as slaves to work in the mines and do his bidding.
"Plague of the Zombies" is an essential zombie film for a number of reasons. It may not be a gory movie, but it's Gothic atmosphere more than makes up for it. The dead themselves are creepy, almost mindless drones that work and stalk en masse, predating the hordes of the dead Romero would use in his films-one wouldn't be shocked if "Plague" was a big influence on "Night of the Living Dead." It's also very well acted film, with most of the cast delivering fine performances, with Carson in particular making for a fun villain. Oh, and the zombie make-up is great, and much better looking than the type found in earlier films.
That out of the way, the most striking thing about the movie is it's social commentary. The fact that Hamilton is bringing the dead back to work for him has a striking political subtext of the selfish aristocracy and their exploitation of the working class that is positively Marxist. Sorry George, but as far as the zombie as a tool for Left Wing political commentary goes, Hammer did it first.
All in all, "Plague of the Zombies" is a must for zombie fans and fans of British Horror in general, that's also smarter than most zombie films that came before or during that time. See it if you want a good, creepy flick with some smart things to say.
Hammer would return to the world of the dead with the campy but fun 1974 Kung-Fu/Horror hybrid "Legend of the 7 Golden Vampires", which was also one of their last movies.