In the History of the Celtic Peoples, author John D. Heinmiller examines history from a unique perspective. In focusing on the Celtic peoples, the peoples from the Britannic Isles to the Iberian Peninsula and the northern part of the modern nation of Italy, Heinmiller argues that it is the Celts who were and are the real dynamic force of Europe from the 15th Century onward. Though the position is controversial, Heinmiller presents the evidence in this history as clearly as he can.

In the last book, the Revival of the Celtic Spirit, Heinmiller discusses the history of the Celts in the modern age. Ancient Celtic principles, long dormant, begin to revive in the Celtic world and spread throughout the world, though not without pain and turmoil.

In this history, the author tries to use the actual names of places, not their anglicized names. Thus, Rome becomes Roma, Italy becomes Italia, Normandy becomes Normandie, etc. Even the names of people and kings are adjusted, the English Henry is the French Henri and the Spanish Henrique. The French Philip becomes Philippe while if he is Spanish he is known as Filipe. This, however, is not taken all the way; for example most readers would not realize that Bourgogne is the true name of Burgundy after all. Still, the author wants the reader to be aware of the actual names.