Where in literature did Merlin the sorcerer first appear?

Merlin the sorcerer first appeared in Geoffrey of Monmouth’s The History of the Kings of Britain (1137).

This Latin prose work by the English chronicler also helped build the legend of Merlin’s protégé, King Arthur.

When was the SAT first administered in the U.S.? The College Board first administered the Scholastic Aptitude Test (SAT) in June 1926. More than 8,000 applicants took the test, most of them applicants to elite colleges such as Harvard, Princeton, and Yale.…
Who was the first woman to win the Pulitzer Prize for fiction? The first woman to win the Pulitzer Prize for fiction was Edith Wharton (1862-1937) in 1921 for The Age of Innocence.
How many times has Norman Mailer been married? Norman Mailer has been married six times.
Who was the first woman to be awarded the Nobel Prize in Literature? Selma LagerlOf of Sweden was awarded the Nobel Prize in Literature in 1909. She is known for such works as Jerusalem (1901-02), a collection of stories about Swedish peasant life.
Who received the first Caldecott Medal? The illustrator's counterpart to the Newbery Medal, named for English illustrator Randolph Caldecott, was first awarded in 1938 to Dorothy P. Lathrop for Animals of the Bible.
Who received the first National Book Award for Fiction? Nelson Algren received the first National Book Award for Fiction in 1950 for The Man with the Golden Arm.