A survey of their history, with the details of their life.
It doesn't go into what archeology can show of their pre-history, but it starts with Lycurgus, who may, actually, be a god turned into a founder, rather than a man. And the legend of Helen of Troy, who was Helen of Sparta first, and how the legends of the beauty and looseness of Spartan women often pointed back to her.
It has biographies of interesting Spartans along the way. Like Cynisca, the Spartan princess who won an Olympic olive wreath twice. Women were not even allowed to watch the games (except, perhaps, certain priestess involved in the rites), but the winner of a horse race was the person who breed and trained the horses. It also has details of Greek life. Like the immense importance of guest-friends, xenos, which is a ritual, hereditary relationship that can even trump your city. How the Spartans, unlike other Greeks, did not distinguish between mere strangers, other Greeks, and barbarian foreigners. How the Spartan women, for all their much talked about power, did not have any all-female religious rites, unlike other Greek -- though that may have been because actual Spartans, though very religious, did not perform rites for Demeter -- or Dionysus either -- probably because that was helot stuff, all the agriculture.
It also covers their history down to their decline, to the revolts of the Messanian helots that finally resulted in their freedom and erecting a new city (with Athenian help) Messene, which drew back Messanians who had fled earlier (and been in the habit of making Olympian dedications to stick in Sparta's eye -- and finally to the era where a usurper actually claimed the throne and married a non-Spartan woman. Neither Phillip nor Alexander the Great had ever really bothered to conquer it, but just left it out, superfluous. Rome finally brought it to heel.
An interesting survey.