Yes, there really was a king of Scotland named Macbeth; however, Shakespeare's play does not present an accurate picture of the real King Macbeth. Mac Bethand mac Findlaich was King of the Scots from 1040 to 1057. Before Macbeth, there was a king named Duncan, and he was killed by Macbeth, but certainly not as described in Shakespeare's play--instead, the real Macbeth slew Duncan on the battlefield during a raid. After Duncan's death, Macbeth became king and was unchallenged by others in the area. During the later years of his reign, Macbeth got into a disagreement with England, and Scotland was raided by the English army, headed by Siward. Macbeth did not survive this raid and was killed by Duncan's son, Malcolm III.