Why doesnt Macbeth use his power as king to get rid of Banquo?

In
,utilizesto kill . I would suggest there are multiple reasons as to why he
does so.

First of all, it is worth keeping in mind that kings did not
actually hold unlimited power (and this is especially the case for medieval kingship). Thus,
having possession of the crown would not have given Macbeth free license to abuse that power.
Quite on the contrary, traditional kingship was relational, with kings and nobles owing one
another certain obligations and responsibilities. If Macbeth had taken advantage of his power in
order to destroy one of his supporters, that would have very much eroded his own support base.
Indeed, this is actually a key theme of the play, given that Macbeth himself is characterized as
a tyrant, a factor which contributes to his downfall.

Furthermore, it's worth
noting that Macbeth came to the throne through the murder of his predecessor, , so you could
imagine that Macbeth himself would have needed to proceed very carefully in the aftermath of his
usurpation, lest he himself fall under suspicion. Politically, he wishes to kill Banquo in order
to secure his dynasty, but doing so in the open would have been risky (as it begs the question
of why he's suddenly turned on Banquo). Remember, Macbeth very much does not want people asking
these kinds of questions. At the same time, you should also keep in mind that Banquo himself was
with Macbeth during the encounter withand so possesses knowledge that Macbeth would very much
have an interest in keeping suppressed.