From the back of the book:
The Aslan know no emperor, no moot, no grand fleet, no central government of any kind. Their society is founded upon Aslan families and the intricate interrelationships knitting them together. These families form larger prides, and these prides form even larger clans, over 4,000 in number and bound by common heritage and tradition. An Aslan’s allegiance is to their clan lord and the clan that he leads.
Explore the inner workings of a clan, learn about the secret warrior schools, and see what life inside the Aslan Hierate is really like – insights rarely granted to outsiders. Clans of the Aslan provides tips and ideas on running a campaign set amongst the Aslan, along with new options for creating and playing Aslan Travellers. Furthermore, Clans of the Aslan provides rules for creating and running your own clans, as well as descriptions of important Aslan clans and worlds drawn from across Charted Space.