Until now the key taxonomic reference for the entire Palearctic region has been Vaurie's seminal work published 40 years ago. This major new book seeks to embrace the many advantages in our knowledge of Palearctic birds and to present a complete taxonomic treatment of every species in the region. Every subspecies will be listed together with identification criteria and complemented with biometric data. There will be a detailed distribution map for every species. This book will be an indispensable reference for anyone with an interest in Palearctic birds and will be completed in two volumes - the volume on non-passerine will follow in about three years.