From publisher blurb:
The region known as the Centaur Borderlands is a stretch of land running from the western bank of the Havenbrook River to the western edge of the Sinless Wood. The Centaur tribes ostensibly control this strip of land all the way down to the Clovenhoof Gulf, but the southern region is hotly contested, with cromags, trolls, and other servants of Gianthome seeking to wrestle controls of the River mouth from the centaurs.
This book contains all the information you need to bring the centaur borderlands to life in your Odysseys & Overlords campaign. Within these pages you will find information on the centaur tribes that call the borderlands home, the means by which they govern themselves, and information about the renegade herd who eschew the ways of the other tribes. You will also find information on the allies and enemies of the centaurs who populate the region, including new monsters for use in your game. Lastly, this book offers options for allowing players to assume the roles of centaurs as a playable genus.