Confidence votes 169. Invictus, meaning unconquerable or undefeated in Latin, is a poem by William Ernest Henley. The poem was written while Henley was in the hospital being treated for tuberculosis of the bone, also known as Pott's disease.n analysis of the poem: Out of the nigh t that covers me, Black as the pit from pole to pole, I thank whatever gods may be For my unconquerable soul. In the first stanza the poem's speaker prays in the dark to whatever gods may be a prayer of thanks for his unconquerable soul..