Identify this music please

The religious chanting starting right at the start of the following video, what is it? I have heard it in the show the Tudors before.

https://www.youtube.com/watch?v=VisqRp_RGl4&list=UU-Jv_5VAlgw0cspftdxh70Q

There are three pieces in that clip. It starts with A Howling Wilderness - The Death Of Jane Seymour by Trevor Morris, then changes to Heart of Courage by Two Steps From Hell , and ends with Tale of a Haunted Banker by Christopher Young.

The clip appears to be part of a series compiled and annotated by a great admirer of Adolf Hitler, btw. Just in case the OP didn’t realise that…