"Don" Google to the rescue!
This page may help, regarding the term "Don"
ce.berkeley.edu/~coby/essays/figaro.htm
etymonline.com/index.php?l=d&p=15
don (n.)
1523, from Sp. or Port. don, title of respect, from L. dominus "lord, master." The university sense is c.1660, originally student slang; underworld sense is 1952, from It. don, from L.L. domnus, from L. dominus (see domain). Don Juan "philanderer" is from the legendary dissolute Sp. nobleman dramatized by Gabriel Tellez in "Convivado de Piedra" and popularized in Eng. by Lord Byron. The fem. form is Dona (Sp./Port.), Donna (It.).
literaturecollection.com/a/lord-byron/don-juan/12/
csus.edu/phil/brochure/spring00.htm
We will trace the development of the 'Don Juan' myth from Molina's original play through the later treatments of Mozart, Kierkegaard, Byron, and Bernard Shaw.
And, here is Asimov's Annotated Don Juan
homepage.mac.com/jhjenkins/Asimov/Books/Book130.htm