Fata Morgana (n.)

1818, literally "Fairy Morgana," mirage especially common in the Strait of Messina, Italy, from Morgana, the "Morgan le Fay" of Anglo-French poetry, sister of King Arthur, located in Calabria by Norman settlers. Morgan is Welsh, "sea-dweller." There is perhaps, too, here an influence of Arabic marjan, literally "pearl," also a fem. proper name, popularly the name of a sorceress.