'An Apology for Poetry' is literary piece of work of -

Sir Philip Sidney was an Elizabethan courtier, statesman, soldier, poet, and patron of scholars and poets considered the ideal gentleman of his day.
After Shakespeare’s sonnets, Sidney’s Astrophel and Stella is considered the finest Elizabethan sonnet cycle.

His other literary works are:
- An Apology for Poetry/The Defence of Poesie (a critical treatise)
- Arcadia (1590), a book that bears the embryo of the English novel.

Source: Britannica.com ও An ABC of English Literature - Dr. M Mofizar Rahman।