Background
"Death, Be Not Proud" is a sonnet by John Donne. It was published in 1633, after Donne’s death, although he wrote the poem in 1609. It is one of nineteen sonnets comprising Donne’s Holy Sonnets.

Structure
The poem is a Petrarchan, or Italian, sonnet. It is composed of 14 total lines. The first eight lines have an ABBA ABBA rhyme scheme. The final six lines have a CDDC EE rhyme scheme. However, it is worth taking noting the EE scheme of the final two lines are made with off rhymes.

Analysis
Death, be not proud, though some have called thee
Mighty and dreadful, for thou art not so;

The poem opens with a bold statement directed at a personified Death. It is not only the capitalization of the letter ‘D’ that shows the personification but also the way the entity is addressed. The speaker (henceforth referred to with male pronouns) makes a speech to Death as if he were speaking to a person. He tells Death not to feel proud; it is not as powerful as most assert it to be. By doing so, the speaker demonstrates the opposite of the fear most feel toward Death.

For those whom thou think’st thou dost overthrow
Die not, poor Death, nor yet canst thou kill me.

The speaker claims those who Death takes, or believes to have taken, do not die in actuality. The deceased are not defeated or overthrown, indicating he is assigning a more spiritual belief to what truly dying means. It can be presumed the speaker feels strength in his spirituality based off his assertion that Death cannot kill him either, hinting the reader will learn more about the speaker’s spiritual view on dying as the poem progresses.

From rest and sleep, which but thy pictures be,
Much pleasure; then from thee much more must flow,

Resting and sleeping are merely impressions of Death and not the real thing. People typically enjoy resting and sleeping, which once again undermines the frightful importance ordinarily assigned to Death. The speaker tells Death it must have more to offer given these are but small likenesses of it.

And soonest our best men with thee do go,
Rest of their bones, and soul’s delivery.

In these two lines, further insight to the spiritual nature of dying is revealed to the reader. The speaker says the "best men" go with Death rather than telling it as Death taking the men, reiterating the notion that Death is not as mighty as it is made out to be. The idea of an afterlife is suggested when the speaker mentions the delivered souls of the best men. Their physical bodies will be laid to rest while their souls will rejoice in eternal glory. Neither of those are devastating prospects, not only rendering what Death believes it brings insubstantial but actually contradicting what is believed to be its intention.

Thou art slave to fate, chance, kings, and desperate men,
And dost with poison, war, and sickness dwell,

The speaker continued to take all power away from Death, now being knocked down from being in charge to being a slave. Death does not choose who to take or when to take them, but is at the mercy of "fate, chance, kings and desperate men." Death can only take those who are meant to die, are in accidents, are in a war, or perhaps even take their own life due to desperation. Death is not able to pick and choose whom to take, reaffirmed in the following line claiming Death only resides with "poison, war, and sickness."

And poppy or charms can make us sleep as well
And better than thy stroke; why swell’st thou then?

Death has long been referred to as an "eternal sleep." In this way, the speaker has used another method of denying Death’s potency. The speaker mentioned earlier that sleep is a picture of Death. Here, he extends this notion that even its own picture has external causes. Poppies are seeds that can aid in falling asleep. Even "charms" are mentioned, most likely alluding to magic. This indicates the speaker thinks even magic has greater power than Death. The speaker’s question "why swell’st thou then?" begs of Death to answer why it is so full of pride.

One short sleep past, we wake eternally
And death shall be no more; Death, thou shalt die.

Though the final two lines may be slightly more confusing to the reader at first glance, they are in keeping with the overall message and tone of the poem. In the line "One short sleep past, we wake eternally" the speaker again alludes to the idea of an eternal afterlife. The "short sleep past" is passing beyond just sleeping to physical death. However, physical death may come but spiritual life is eternal. The speaker is letting Death know it cannot overpower that. "Death, thou shalt die" denotes the end of Death’s supposed reign and the impression people have of it. The perception of Death that strikes fear in the hearts of people will cease to exist.

Summary
This poem suits the metaphysical label of Donne’s work in the subject matter it tackles, particularly the way in which it is approached. The speaker is witty, the imagery is strange and complex, and the poem presents many of what appear to be contradictions. The speaker of the poem personifies Death and goes on to depreciate the might of Death. The speaker details the way in which Death is not in control and the reasons it is not altogether frightening. By poem’s end, the speaker has established a very clear point and presented a well thought out explanation. He ends it by directly telling Death it will "die," meaning no longer exist.

Theme
The prominent theme of the poem is mortality. It is worth noting there is also a theme of spirituality, or even specifically religion. The speaker addresses Death throughout the poem making it clear to the reader mortality is being discussed. Many of the views presented on dying and the afterlife are very centered on Christian fundamental beliefs.

References
-poetryfoundation.org/poem/173363
-poets.org/poetsorg/text/poetic-form-sonnet
-en.wikipedia.org/wiki/Death_Be_Not_Proud_%28poem%29
-study.com/academy/lesson/metaphysical-poetry-definition-characteristics-examples.html