Who was the brother of 16th century poet group the Wilton Circle's leader?
Wilton Circle: The Wilton Circle were an influential group of 16th-century English poets, led by Mary Sidney. Mary Sidney:  By the age of 39, she was listed with her brother Philip Sidney, Edmund Spenser, and William Shakespeare, as one of the notable authors of her time in the verse miscellany by John Bodenham, "Belvedere".
Philip Sidney