The early history of Earth covers such vast stretches of time that years, centuries, and even millennia become virtually meaningless. Instead, paleontologists and scientists who study geochronology divide time into periods and eras. What humans commonly refer to as the “Ice Age” is actually a series of fluctuating climate events that have occurred throughout the planet’s history. These ongoing historical phenomena are difficult to conceptualize because of both the time frame involved and the natural process by which they cyclically unfold.

The early history of Earth covers such vast stretches of time that years, centuries, and even millennia become virtually meaningless. Instead, paleontologists and scientists who study geochronology divide time into periods and eras. The current view of science is that Earth is around 4.6 billion years old, but despite all of the scientific advances made in the past few centuries, including an enhanced understanding of Earth’s geological past, relatively little is known about the planet’s early history.

To the Aztecs, Huitzilopochtli wore a blue-green hummingbird helmet and was draped in pure white heron feathers. He carried a smoking mirror, an obsidian mirror, a shield, darts, and the serpent Xiuhcoatl that carried with it the fury and might of the sun. Everything about him - from his clothes to his weapons - emanated and defined royalty.

Today, Russia is the biggest and one of the most populous countries in the world. From the early, primitive state-like formations in the 9th century, all the way to the creation of the first true tsardom of Russia in 1547, the history of medieval Russia is one filled with constant struggles for power, personal rivalries between various princes, bloody wars, and a search for identity.

Completing the Meiji Restoration that heralded the dawn of a new era for both Japan and Asia, the island nation found itself thrust into the modern world, a world of industry and conquest. Flexing its new muscles, the burgeoning power soon came to blows with the regional power that for centuries dominated the area politically and culturally: China. Also seeking to modernize in the wake of Western exploitation, China struggled to adapt to the changing times, doing everything it could to maintain a balance between modernity and tradition. Japan found that balance.

King Edward I was the first of three Edwards who reigned in perfect succession. He was one of the most important kings in English history, but he was also one of the most controversial. This was the king who subdued Wales and fought Scotland to a standstill for much of his reign. He battled leading Scottish figures that are recognizable to even novice history students. Both William Wallace and Robert the Bruce butted heads with this English ruler.

In the Age of Exploration, the British began building an enormous and highly profitable foreign empire. While the British Empire initially lagged behind other European powers such as Spain and Portugal, it still managed to colonize the New World and discover highly-lucrative trade routes.

The terrible conflict that dominated the mid-19th century, the Crimean War, killed at least 800,000 men and pitted Russia against a formidable coalition of Britain, France and the Ottoman Empire. It was a war for territory, provoked by fear that if the Ottoman Empire were to collapse then Russia could control a huge swathe of land from the Balkans to the Persian Gulf. But it was also a war of religion, driven by a fervent, populist and ever more ferocious belief by the Tsar and his ministers that it was Russia's task to rule all Orthodox Christians and control the Holy Land.

The Knights Templar has established itself as the most popular military organization of medieval times. Everyone has heard of the order, and everyone is familiar with the image of a medieval Crusader knight with a red cross on their white uniform. But who exactly were the Templars? What was their purpose? And are the rumors about their secretive nature true?

For centuries, Denmark “punched above its weight” and was a major player on the European stage. Many know about the Danish Vikings and their voyages of conquest and discovery, but Denmark is more than just those medieval raiders and traders, even though interest in their adventures is at an all-time high today.

Ethiopia has a long history. It boasts one of the longest-running continuous civilizations on the planet; even the origins of humanity have been traced back to Ethiopia. Ethiopian kingdoms date back to the days of the Bible, and mentions of Ethiopian monarchs can be found all throughout the historical record.

The Viking Age - from 750 to 1050 saw an unprecedented expansion of the Scandinavian peoples into the wider world. As traders and raiders, explorers and colonists, they ranged from eastern North America to the Asian steppe. But for centuries, the Vikings have been seen through the eyes of others, distorted to suit the tastes of medieval clerics and Elizabethan playwrights, Victorian imperialists, Nazis, and more. None of these appropriations capture the real Vikings, or the richness and sophistication of their culture.

The Scythians were nomadic horsemen who ranged wide across the grasslands of the Asian steppe from the Altai mountains in the east to the Great Hungarian Plain in the first millennium BC. Their steppe homeland bordered on a number of sedentary states to the south and there were, inevitably, numerous interactions between the nomads and their neighbours. The Scythians fought the Persians on a number of occasions, in one battle killing their king and on another occasion driving the invading army of Darius the Great from the steppe.

Roughly half the world's population speaks languages derived from a shared linguistic source known as Proto-Indo-European. But who were the early speakers of this ancient mother tongue, and how did they manage to spread it around the globe? The Horse, the Wheel, and Language solves a puzzle that has vexed scholars for two centuries and recovers a magnificent and influential civilization from the past.

Why did humans abandon hunting and gathering for sedentary communities dependent on livestock and cereal grains and governed by precursors of today's states? Most people believe that plant and animal domestication allowed humans, finally, to settle down and form agricultural villages, towns, and states, which made possible civilization, law, public order, and a presumably secure way of living. But archaeological and historical evidence challenges this narrative.