This is not a whole sentence. It is a subordinate clause which functions either as a subject or as an object of another main clause. To give example:
"You have to write an essay about your ancestry preserved by the people."
"Your ancestry preserved by the people will be your essay homework for next week."
I mean all of your phrase may be the subject.
Or It maybe l�ke that in a poem:
You have to bear the burden of,
Your ancestry preserved by the people