Was Macbeth a real person?

Macbeth did indeed ascend the Scottish throne after the death of King Duncan I, but Duncan was a fairly young man (unlike the old and wise Duncan of the play) and was by no means a very able ruler. He was not murdered in his bed, but defeated and killed by Macbeth at the Battle of Pitgaveny on the 14th August, 1040 in what was a generally popular dynastic coup. As king, Macbeth seemed to bring order and stability to Scotland, so much so that he was able to leave and go on a pilgrimage to Rome in 1050. However, the King of England, (Edward The Confessor) made an massive invasion bid under the command of Earl Siward in 1054 which severely weakened Scotland once again. Although Macbeth's regime survived that crisis, Duncan's son Malcolm Canmore (the future Malcolm III) was later able to defeat Macbeth at the Battle of Lumphanam on the 15th August, 1057. Mortally wounded, Macbeth died at Scone shortly afterwards and was succeeded as king by his stepson, Lulach (as opposed to Malcolm). Unlike in the Shakespeare play, Macbeth was not considered a tyrant by his contemporaries and had a generally very successful reign lasting 17 years. The reason this may have changed in Shakespeare's Macbeth is because Shakespeare made his plays to please the English monarchy, and the real history does not portray England as a very moral country.