Shakespeare's authorship was first questioned in the middle of the 19th century. At that time the idea that Shakespeare was the greatest writer of all time had become widespread. Shakespeare had a simple background, and some details of his life are unknown. These facts seemed to be incompatible with his poetic eminence and his reputation for genius. Some people suspected that Shakespeare might not have written the works attributed to him. The controversy has since spawned a vast body of literature, and 80 authorship candidates have been proposed, including Francis Bacon, the 6th Earl of Derby, Christopher Marlowe, and the 17th Earl of Oxford.