I will play this minor character in the Shakespeare At Sloss production of Macbeth. I am angry at myself; my audition piece was less than fully formed, and I blatantly stumbled on it during the audition itself. Perhaps I could have earned a more full-bodied role if I hadn't bungled my audition.
Yet even a teensy Shakespearean role affords multilayered possibilities. A cursory Googlesearch turned up this:
"Thorfinn, Jarl of Caithness and the Orkneys
This infamous Norse ruler is known as Thorfinn the Great, and he was Macbeth's northern neighbor almost from boyhood, for Thorfinn was only five when he inherited Caithness... Thorfinn swore allegiance to the Norwegian king at age 16, so his loyalties were, at best, divided."
Divided loyalties contrast interestingly with my line "Well, march we on,
To give obedience where 'tis truly owed..." Perhaps Caithness/Thorfinn is trying to reassure himself that his decision to battle Macbeth is the correct one, rather than simply stating an easily-achieved point of view.
I hope I have rocked your world with this information.