Did anyone know?

[Boromir88]

I was thinking, the Istari are far from your karblang Harry Potter wizards. However, they do have their own powers, that of course a mortal person would not, and to mortals were held as "wizards?"

The Istari are maia, and I was wondering if anyone (besides themselves) on middle-earth knew who truthfully the Istari were? Or if they just thought they were old, wise, counselling wizards?

If anyone knew, I would have to say Cirdan, he did give Gandalf his ring, and only trusted Gandalf, which makes me think that he probably knew "Olorin."

As for some of the others, I wouldn't doubt it if Galadriel, Elrond, Celeborn, or Glorfindel knew, but this I'm not for certain. I would like to know if anyone knew for certain, that Gandalf, is essentially a maia? That is anyone from middle-earth, not including the other Istari.