Tacitus 
Germania 

This book written by the Roman historian Publius Cornelius Tacitus around 98 AD and originally entitled On the Origin and Situation of the Germans, is a historical and ethnographic work on the Germanic peoples outside the Roman Empire. It begins with a description of the lands, laws, and customs of the Germanic people, then describes individual peoples, beginning with those dwelling closest to Roman lands and ending on the uttermost shores of the Baltic, among the amber-gathering Aesti, the Fenni, and the unknown peoples beyond them.