How is Death "slave to fate, chance, kings, and desperate men" in the poem "Death be not proud"?

Ah a holy sonnet by cleric John Donne!!! Basically it is a holy spiritual sonnet in which the author, Donne, claims that death would not exist if it were not for man's nature. When he says slave to fate and chance, he is saying that death does not have the choice of who is killed, but rather is slave to the fact that these instances exist. Kings and desperate men-kings were believed to be brought to earth by the heavens and were then sent back once a successor was chosen. Desperate men would be soldiers who would fight for land, or leadership.