I assume you mean the Tranter book - simply called 'Macbeth the King' I think - as far from Shakespeare as you could possibly get.
Most of Tranter's 60-odd Scots novels are a remarkable introduction to Scots history; The Wallace, The Bruce trilogy. Lord of the Isles, The James Sixth/1st Trilogy, The McGregor trilogy.
Well-researched, readable history - very few 'gluggers' among them.
Jim Carroll