Todd Sand bastard of AZ

It's probably been mentioned in this thread already. In case not... In my reread in ASoS, I just read Jorah telling Dany of the 3,000 Unsullied who defended Qohor against a Dothraki army several times their size. The Dothraki broke their mounted forces upon the Unsullieds' shield wall and spears. Guessing it has to be a reference to Thermopylae.