One episode about it which sounded impressive is that several friends of him used to call him affectionately 'the old queen'. I read it in a book of their biography.
cuz he woz a queen as simple as that, and he changed his name AFTER they formed Queen dude.
reasons may be:
"I like the sound of it, it's very grand, it's pompous, it's short, it's a tribute to the Birtish monarch, it's gay, it's fairy etc etc.
Brian: "He said to me (about My Fairy King) the mother in this song is my mother, so i am Mercury etc etc" So they were already Queen for some time already before he changed his name, don't know when he wrote the song though...i think he knew already he wanted to change his name to Mercury...hmmm...wot woz the question again? -.-"
He apparently thought up the name Queen while still in college. Something short, grand, etc
Sort of like the drummer coming up with Aerosmith while in school.
Freddie changed his name after the last lines of My Fairy King (see The Untold Story)
Well, I guess I am not learning you anything here but i'll say it anyway. The band was called Smile before Freddie was the lead singer. Brian was in this band with a guy named Tim Staffel, the lead singer; then they met Roger to join the group. After a while though, Smile wasnt going anywhere. Then, Brian and Roger met Freddie, who was a friend of Tim. After Freddie heard the boys play, he said to them that their music was great - but that they should be a lot more demonstrative in the way they play their songs, and that they should use more of the visual aspect with all kinds of accessories and costumes. After a while, Tim left the band and Freddie accepted to join it as the lead singer. That's the point where the name Smile left... Naming the group as Queen was of course Freddie's suggestion (while Brian and Roger's reaction to this was quite disdainful...) and he said about it: 'It's just a name but it's very regal and it sound splendid. It's a strong name, very universal and immediate. It had lots of visual potential and was open to all sorts of interpretations. I was certainly aware of the gay connotations, but it was only one facet of it'.