"Sonnet 18" is a sonnet written by English poet and playwright William Shakespeare. The poem was likely written in the 1590s, though it was not published until 1609. Like many of Shakespeare's sonnets, the poem wrestles with the nature of beauty and with the capacity of poetry to represent that beauty. Praising an anonymous person (usually believed to be a young man), the poem tries out a number of clichéd metaphors and similes, and finds each of them wanting. It then develops a highly original and unusual simile: the young man's beauty can be best expressed by comparing him to the poem itself.