Having murdered his king to become king himself, Macbeth finds that in order to to maintain his position he must conduct a reign of terror against his opponents. He has followed an irresistible ambition, but now he finds that it's been a hollow quest.
Towards the end of Act 5, Macbeth learns that his Queen, Lady Macbeth, has died – probably taking her own life, having been driven to madness by guilt over their crimes. He receives the news with resignation: "She would have died anyway". Exhausted and disillusioned, and just about at the end of his tether, he delivers one of the most famous soliloquies in all of Shakespeare:
Tomorrow, and tomorrow, and tomorrow,
Creeps in this petty pace from day to day
To the last syllable of recorded time,
And all our yesterdays have lighted fools
The way to dusty death. Out, out, brief candle!
Life's but a walking shadow, a poor player
That struts and frets his hour upon the stage
And then is heard no more: it is a tale
Told by an idiot, full of sound and fury,
Signifying nothing.
Thanks to nosweatshakespeare.com for the context!
© Haydn Thompson 2021