Between 1861 and 1865, the clash of the greatest armies the Western hemisphere had ever seen turned small towns, little-known streams, and obscure meadows in the American countryside into names we will always remember. In those great battles, those streams ran red with blood-and the United States was truly born.

Following the surge of interest and pride in Celtic identity since the 19th century, much of what we thought we knew about the Celts has been radically transformed. In The Celtic World, discover the incredible story of the Celtic-speaking peoples, whose art, language, and culture once spread from Ireland to Austria. This series of 24 enlightening lectures explains the traditional historical view of who the Celts were, then contrasts it with brand-new evidence from DNA analysis and archeology that totally changes our perspective on where the Celts came from.

Look beyond the abstract dates and figures, kings and queens, and battles and wars that make up so many historical accounts. Over the course of 48 richly detailed lectures, Professor Garland covers the breadth and depth of human history from the perspective of the so-called ordinary people, from its earliest beginnings through the Middle Ages.

Mesopotamia is the ancient name for the region that is now Iraq, a remarkably advanced civilization that flourished for two-thirds of the time that civilization has existed on Earth. Mesopotamians mastered irrigation agriculture; built the first complex urban societies; developed writing, literature, and law; and united vast regions through warfare and diplomacy. While civilizations like Greece and Rome have an unbroken tradition of written histories, the rich history of Mesopotamia has only been recently rediscovered, thanks to the decipherment of Mesopotamia's cuneiform writing less than 200 years ago.

Language defines us as a species, placing humans head and shoulders above even the most proficient animal communicators. But it also beguiles us with its endless mysteries, allowing us to ponder why different languages emerged, why there isn't simply a single language, how languages change over time and whether that's good or bad, and how languages die out and become extinct.

Economic forces are everywhere around you. But that doesn't mean you need to passively accept whatever outcome those forces might press upon you. Instead, with these 12 fast-moving and crystal clear lectures, you can learn how to use a small handful of basic nuts-and-bolts principles to turn those same forces to your own advantage.

Jazz is a uniquely American art form, one of America's great contributions to not only musical culture, but world culture, with each generation of musicians applying new levels of creativity that take the music in unexpected directions that defy definition, category, and stagnation. Now you can learn the basics and history of this intoxicating genre in an eight-lecture series that is as free-flowing and original as the art form itself.

Thor, Odin, Loki, Freyja, the Valkyries, Valhalla, Ragnarok — many of the places we encounter these and other names, places, and events from Norse mythology in daily life and pop culture are connected to the medieval sources in name only.

Grasp the important ideas that have served as the backbone of philosophy across the ages with this extraordinary 60-lecture series. This is your opportunity to explore the enormous range of philosophical perspectives and ponder the most important and enduring of human questions-without spending your life poring over dense philosophical texts.