In the years that followed the groundbreaking and monster-defining films Dracula (1931) and Frankenstein (1931), Werewolf of London followed in their footsteps. I know most people think of Lon Chaney Jr's magnificent performance in The Wolfman (1941) as the one that started it all. However, I would argue that Werewolf of London laid the foundation for The Wolfman to build upon.
Director Stuart Walker gives us a beautifully made film with a wonderful screenplay that is just as good as Dracula and Frankenstein. In Werewolf of London, the trouble starts in Tibet where Dr. Glendon gets bitten by a mysterious creature while trying to find a rare flower. As he returns to London, the juice of this flower turns out to be the only thing that keeps his "werewolfery" in check. [I love the use of the term in the movie!] Dr. Gordon is portrayed by Henry Hull [Boys Town] who definitely takes center stage and gives us a solid performance. Chaney is better but Hull is a fine actor nonetheless. His makeup is, surprisingly done by Jack Pierce who is uncredited in the film. It's not up to his usual standards but he would go on to perfect it in The Wolfman. Warner Oland [Charlie Chan movies] plays Dr. Glendon's nemesis, Dr. Yogami. He plays off of Hull quite nicely. A shout out also has to go to the two drunk old lady innkeepers who steal the show every time they appear on screen.
If you're a fan of the Wolfman character, then this one is a must see. It's a gigantic step forward from 1925's silent film Wolf Blood and shows you how far cinema came in such a short time. The copy I watched was from the Universal Legacy Series DVD set which I had the good fortune of coming across at a used bookstore. It is lovingly restored and is the best way to see this film unless you can catch it at a local theater.
For more info check out the film's entry in IMDB.