From the back of the book:
"For twelve long years, the Clans have savaged Inner Sphere worlds and armies alike. But who are they? What drives them? This comprehensive report finally puts to rest more than a decade's worth of speculation about the decendants of Kerensky. The information in this document may be the Inner Sphere's greatest weapon against their Clan foes.
The Clans: Warriors of Kerensky describes in detail all the elements that forged the Clans into the ultimate warrior society, including their history, government, customs and homeworlds. This book also covers the Clans' current status and holdings, including a map of Clan space. The Clans: Warriors of Kerensky also features the insignias of each of the original twenty Clans."