The ghost of Banquo.
Macbeth's coronation
Macbeth sees the ghost of the recently murdered Banquo.
No, Lady Macbeth is not aware that Macbeth has planned the death of Banquo and Fleance.
Macbeth kills him because Banquo starts to work out that Macbeth killed dDuncan
The ghost of Banquo.
Macbeth's coronation
The soldiers are on night watch at the castle in the opening of the play "Macbeth." They are accompanied by Banquo and Macbeth.
Three for Banquo, six men to Macduff's castle
Macbeth kills Banquo in the play and then Banquo's ghost haunts Macbeth.
Macbeth's best friend was Banquo. They fought together in battle before Macbeth's rise to power.
Macbeth sees the ghost of the recently murdered Banquo.
Macbeth kills Banquo in the play and then Banquo's ghost haunts Macbeth.
No, Lady Macbeth is not aware that Macbeth has planned the death of Banquo and Fleance.
Macbeth's soldiers do not kill Banquo, Macbeth hires three murderers to do the job.
In Act 3 of Macbeth, Macbeth becomes suspicious that Banquo poses a threat to his throne. He worries that Banquo's descendants will inherit the crown, as the witches prophesied. This suspicion leads Macbeth to plot Banquo's murder.
*Banquo. Macbeth's best friend is Banquo, but he is also Macbeth's enemy. After the meeting with the witches, Macbeth finds out that he will become the Thane of Cawdor and the King of Scotland. Eventually, he achieves both of these prophecies. Banquo, Macbeth, and Lady Macbeth are the only people that know about the witches. Banquo becomes suspicious of Macbeth because Macbeth fulfills the prophecy after King Duncan is murdered, and Macbeth acknowledges this fact. Basically, Macbeth doesn't trust Banquo.