The poem introduces Colin Clout, a folk character originated by John Skelton, and depicts his life as a shepherd through the twelve months of the year. The "Calender" encompasses considerable formal innovations, anticipating the even more virtuosic "Countess of Pembroke's Arcadia" (The "Old" "Arcadia," 1580), the classic pastoral romance by Sir Philip Sidney, with whom Spenser was acquainted. It is also remarkable for the extensive commentary included with the work in its first publication, ascribed to an "E.K." E.K. is an intelligent, very subtle, and often deeply ironic commentator, who is sometimes assumed to be an alias of Spenser himself. The term sarcasm is first recorded in English in Spenser's poem.