So, I'm going to be playing Deathwatch for the first (proper) time soon. I'm creating my PC ad reading through the rule book, and I've come to a stop at "Giving My Character Life". I don't know how much creative liberty I have in making my backstory, whether or not I am allowed to make up fictional planets or battles, or even people for that matter.
Am I allowed to say, for instance, "My Space Wolf fought with great strength and valor on Chiron Beta Prime in the effort of freeing the enslaved Imperials from their Orcish Overlords; and in exchange was granted the honor of serving on the Deathwatch."?