Todd Jensen writes...

Here's an answer to the question that you asked about who was Duncan's wife. According to Mike Ashley's "Mammoth Book of British Kings and Queens", her name was Sybilla, and she was either the daughter or the sister (written accounts apparently clash on this one) of Earl Siward of Northumbria (who was, in actual history - and Shakespeare's play - the leader of the English army that helped Canmore invade Scotland and overthrow Macbeth; no doubt he was one of the relatives that took Canmore in after Macbeth banished him to England in 1040).