What's the Name of That Book??? discussion

I read this trilogy in 1985 or 1986. I believe that it was written sometimes between the late 1950s to the early 1970s. I believe that it was written by a fairly well known science fiction or fantasy author. I remember that each book involved a war against a different levels of the empire. The first book involved fighting a local lord. The second book involved fighting a regional lord. The third book involved fighting the leader of the empire. I think that it was implied that this was taking place far into the future in what was once the United States. The world involved was essentially based on medieval culture and warfare. I also remember that one of the protagonists was overweight and that at one point his body was described as "gross". Thanks in advance for any help in finding this trilogy.

This is unlikely, but could you possibly be thinking of Lord Kalvan of Otherwhen?

The original book was written in 1965, and there are sequels by other authors written later. The main character thinks at first that he's far into the future in the United States, and it's based on medieval warfare. There is also Prince Sarrask, who was overweight (don't recall the specific word gross though). They definitely work their way up in the battles.

Do you recall anything about gunpower, Princess Rylla, or cross time travel?

Hi Sarah - I looked up Lord Kalvan of Otherwhen. That was not one of the books. Thank you for the tip though.

Solved! The series was Fred Saberhagen's Empire of the East Series and the first three books that I read were:

The Broken Lands
The Black Mountains
Changeling Earth

Glad you found your book series, Brian. Link for first book - The Broken Lands by Fred Saberhagen