Death Be Not Proud

I think this poem is trying to lessen the fear death can inspire. The entire poem uses personification by addressing death directly, as a foe who should not be proud. The line, "Thou art slave to Fate, Chance, kings and desperate men...", very well illustrates this theme. The line is saying that death itself has no power. Death itself is simply a result of things such as fate, chance, and any other number of situation. Death is an inevitable part of life, an therefore should not be feared.  In other words, as John Donne phrased it in the title, Death Be Not Proud. The poem gives all death's credit to its causes, like poison, war, and sickness. Really, death has nothing to be proud of since it can take no responsibility. Death is a mere part of life.