Out of the night that covers me,
Black as the pit from pole to pole,
I thank whatever gods may be
For my unconquerable soul.
In the fell clutch of circumstance
I have not winced nor cried aloud.
Under the bludgeonings of chance
My head is bloody, but unbowed.
Beyond this place of wrath and tears
He doesn’t whine when life gets tough! 
 In “the fell clutch of circumstance”, the word “fell” is being used as an adjective meaning “cruel.” The hard, percussive consonants emphasise the harshness of his fate. 
 When Henley was 19 one his legs had to be amputated below the knee. Immediately after the amputation was completed, doctors informed him that the other leg would also need to be amputated. While ultimately he was able to keep his other leg, it required more surgery. While he was recovering in the infirmary, he wrote this poem.
Invictus