In El Cortesano it's Don Luys Milan … I am not a home for the next few days, but if anyone has the Facsimile of El Maestro published by the Sociedad de la Vihuela a few years ago, he or she could look into the commentary and see if there is any evidence mentioned for Milán, de Milán or similar.
Best Joachim To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html