Macbeth was born in 1005. At the time Scotland was a very violent and troubled country. Although the play of Macbeth was set in the 11th century, William Shakespeare did not write it until the 16th century. When Shakespeare wrote the play King James on the throne. King James was fascinated by witchcraft and perhaps Shakespeare wrote the play so that the king would like it. In Eleventh Century Scotland everyone wanted power. That is why the witches' plan was so successful; Macbeth had a hunger for power. In Act one Macbeth meets with the witches. The witches...
the tension. It makes the audience less jumpy and relaxes them ready for the discovery of the murder.

I feel that the whole unnatural theme to the play makes it a lot more interesting. In the real life of Macbeth, Duncan was killed in battle and Macbeth didn't go mad and died in battle also. Without the witches, the murder and Macbeth going mad there would be hardly any tension and therefore wouldn't be worth reading or watching. Shakespeare has bought a simple story to life with the unnatural happenings and I think it is really effective.