Which sonnet begins 'Shall I compare thee to a summer's day'?

The sonnet that begins “Shall I compare thee to a summer’s day” is Sonnet 18 by William Shakespeare. It is one of the 154 poems published in the 1609 quarto collection commonly known as Shakespeare’s Sonnets.

The speaker initially considers comparing the beloved to a summer day, then rejects the comparison because summer is changeable and brief. Rough winds can damage May’s young flowers, the sun can become too hot or be obscured, and every beautiful thing eventually loses its beauty through accident or the passage of time.

The poem’s central claim is that poetry can preserve the beloved beyond ordinary physical change. Shakespeare says the beloved’s “eternal summer” will not fade because the sonnet itself will continue to live as long as people breathe and read. This idea is often called poetic immortality.

Sonnet 18 belongs to the Fair Youth sequence, the group of poems generally numbered 1–126 in the 1609 collection. Its addressee is never definitively identified, and the poem does not need a biographical identification to work: its lasting subject is the relationship between beauty, time, mortality, and art.