The Unsullied are eunuch slave soldiers, trained from a young age in Astapor to unquestioning obedience and martial prowess. They are used as guards all over the Free Cities. They are sold by the century or the thousand. They make excellent guards, do not loot and will never rape. They also worship a goddess of their own, whose name is kept in secret among them but is known as the Lady of Spears, the Bride of Battle and the Mother of Hosts.
They were most famously used in the Battle of Qohor, where three thousand Unsullied held back a Dothraki khalasar over fifty thousand strong. Only 600 of the Unsullied survived, having killed 12,000 of the Dothraki. To honor the Unsullied, the Dothraki rode in before the Unsullied line, throwing their cut braids down in front of them