This was ancient Greece, and as you can imagine, the Greece of today wouldn't exactly be covering this in school. In fact, nobody really covers this in school because most people want to pretend gayness just popped out of nowhere and hasn't been around forever in all cultures and countries on the planet. I got lucky and found a class all about sex laws, gay laws, gay history, and the history of gay studies.
If you don't believe me, I understand, it's on Wikipedia, and they cite their sources.
http://en.wikipedia.org/wiki/Greek_Homosexuality
That's about the scholarly work in 1978 about all this.
http://en.wikipedia.org/wiki/Homosexuality_in_ancient_Greece
And that's the overview article, which links to the specific articles about the military and the lesbians and whatnot.
The word lesbian come from the Island of Lesbos, because this one female teacher there (Sappho) had sex with a bunch of her students in the same teacher-student fashion, and it was the first time we had records of a woman doing that. But instead of naming it after her, we named it after her island? I guess Lesbian sounds prettier than Sapphic.
EDIT: I was wrong about Sappho. She wasn't a teacher but a poet. There exists no evidence of her being a teacher but for some reason during Victorian times they just made that shit up and a lot of people spread the nonsense to this day, and I got zinged.
