By the time that Shakespeare came to write Sonnet 130, the traditional Petrarchan love sonnet was starting to look pretty worn-out. It seemed that poets, even the very best ones, had exhausted all the possibilities of the form. In particular, the language used in such poems had become cliched, with the same words being used over and over again in comparing the beauty of the speaker's beloved to the beauties of nature. (Lips would be "ruby-red," skin like "alabaster," and so on.)

Throughout Sonnet 130, Shakespeare compares his beloved's beauty to a host of features from the natural world. Nothing particularly original here, one might think. But crucially, Shakespeare turns the old love sonnet conventions upside-down by acknowledging that such comparisons do not redound to the benefit of his beloved. Her eyes are nothing like the sun, her lips aren't as red as coral, and so on. It almost seems as if the speaker is mocking his lover as well as the established conventions of Elizabethan love sonnets.

But this impression is dispelled by the last two lines of the poem, the couplet, in which the speaker says that none of these unflattering comparisons with nature ultimately matter. For he knows that nothing can compare to his beloved:

And yet, by heaven, I think my love as rare

As any she belied with false compare.