What star can be used to work out where due North is?
Currently Polaris. Circa 2500 B.C. Thuban. Around 8000 A.D. Vega
Just about any of them. You look at the circle they make in the sky over a day, or a part of the circle if it's a few hours. The center of the circle is due north or south. Or you might be able to figure the center with just a glance, if you know the patterns of the stars.