A good deal of English poetry is unrhymed, much of it in blank verse, that is, unrhymed iambic pentameter. Introduced into English poetry by Surrey in the middle of the sixteenth century, late in the century it became the standard medium (especially in the hands of Marlowe and Shakespeare) of English drama. In the seventeenth century, Milton used it for Paradise Lost, and it has continued to be used in both dramatic and nondramatic literature. A passage of blank verse that has a rhetorical unity is sometimes called a verse paragraph.