Who was Macbeth?

His full name was Mac Bethad mac Findlaich. He was once the king of Scotland, he was a mysterious king in Scottish history. As a 11th century king, we do not know much about this Macbeth, because most informations are misleading. What we do know is that, Macbeth has tranformed in the hands of William Shakespeare, in his scottish play "Macbeth". Although Shakespeare has changed the historical facts, but I'm pretty sure that Macbeth would be happy to see himself on our text book.