Over the years, PBS has produced a series of programs on the history of empires. In 2003, they made 2 special episodes on Martin Luther. (Liam Neeson provides the narration.) Thanks to Hulu, these are available for your viewing pleasure at any time.
Each is one hour in length, so you may want to come back when you have the time. If you don’t know about Hulu, you can choose between 360 and 480p resolutions, as well as view in full screen mode. You can also check out the other series produced on the Roman Empire, Kingdom of David, etc.