Trying to remember the name of a book/series I read a long time ago...

I know it was a series, maybe just a trilogy.

The main character was a prince and the younger brother of two (i think it was just the 2 brothers).

The father dies (or maybe the older brother kills the father...).

The younger brother goes into hiding.

The story was set in a "middle ages" type setting, but when the main character goes into hiding he finds out the church has been using technologies such as electricity, vacuum's, lightbulbs, etc to run their lives and keep everyone else ignorant (for lack of a better word).

Anyway, I read one or two of the books, never got to read the third, and don't know what happened to any of them.

If this story rings a bell (and I may have gotten a few things wrong cause it's been over a decade since I read the first book) plz let me know. ;D