Jerry said "Incidentally, what's in history books can be biased or even inaccurate too."
Yup! That's why I rely on Sellars & Yateman's 1066 AND ALL THAT for *all* my history needs!
(Actually, for a Yank who didn't grow up on the real thing, it's hilarious to start from the parody and slowly find out what each bit is based on, from the Venomous Bead to the Old Suspender, and not forgetting the Picts, or Painted People (see the Black Watch, the Red Comyn, and Douglasses of all colors).