The Tudors Season 4 Episode 10 (The Tudors s04e10) with title “Death of a Monarchy” airs on Sunday, June 20th 2010 at 09:00 pm via Showtime Network.
Here is summary for The Tudors Season 4 Episode 10 :

The series’ four-season run comes to an end with Henry defeating one more formidable political rival and facing his mortality after dealing with the deaths of longtime friend Charles Brandon and King Francis of France.

Few hours after original series aired on TV, online streaming video for The Tudors Season 4 Episode 10 usually available on Net and of course, if video available, as soon as possible will show you where you can watch this episode for free.