The play begins on a "blasted heath" or "deserted place," depending on which version you may have. However it is said, we find ourselves at the beginning of Act One on a battlefield where the witches have appeared. I always imagine dead bodies strewn about and fog and smoke and the smell of death is in the air. And, as whenever the witches appear, there is thunder, lightning and rain. Indeed. I see the whole play like this: gray and nasty, murky and muddy, dark and bloody. As for when all this messy business takes place, historically: there really was a Macbeth, and he killed King Duncan in the year 1040.
The general setting for Act I of "Macbeth," by William Shakespeare is a battlefield in Scotland.
The play begins with three witches prophesying about the battle that is being fought on that field by Macbeth. This general area is the setting for the first 4 scenes.
Scenes five through seven are set in Macbeth's castle at Inverness in Scotland.
By the end of the act, we know that Macbeth is going to try to become king of Scotland and that, in doing so, he believes that he will need to kill Duncan (the current king) and Duncan's son Malcolm.
The general setting of most of Act I in Macbeth is Scotland in the Middle Ages. The first scene, which features the three witches, takes place in an unspecified "desert place." The second scene takes place at a military camp near Forres (in Scotland), which is where Duncan, the King of Scotland, lives. The Norwegians are currently attacking Scotland with the help of Scottish traitors. Scene 3 takes place on a heath near Forres, where the witches reappear near the battle that is raging between the Scots and the invading Norwegians. Scene 4 takes place in Forres, where Duncan has his castle. Scene 5 takes place in Inverness, where Macbeth and Lady Macbeth have their castle, and Scenes 6 and 7 take place at or near Macbeth's castle, as Duncan journeys to Macbeth's house.