William Shakespeare's Sonnet 55, "Not marble, nor the gilded monuments ...", follows the conventions of a genre of poems comparing poems to eternal monuments that goes back to Horace's Ode 3.30. The narrator of the ode describes the act of poetic creation as follows:
I have created a monument more lasting than bronze
and loftier than the royal structure of the pyramids, ...
In Ode 3.30, Horace says that this poem will enable him to evade death because unlike physical monuments, poems are not subject to erosion by rain or wind, and thus live on forever.
In Sonnet 55, Shakespeare builds on the Horatian theme, saying:
Not marble, nor the gilded monuments
Of princes, shall outlive this powerful rhyme;
Unlike Horace, though, rather than emphasizing his own immortality as a poet, Shakespeare emphasizes that the poem will give his beloved immortality, rescuing his beloved from oblivion and preserving his beloved for all posterity. Thus poetry becomes a defense against death, for even after the body dies, the poet and the subject of the poem live on in the poem.