The Renaissance was a cultural revitalization that spread across Europe, and had repercussions across the globe, but one smallish city-state in Italy was in many ways the epicenter of the thing. Florence, or as Italians might say,...

European exploration had a lot of side effects. When the Old World and the New World began to interact, people, wealth, food, animals, and disease began to flow in both directions. In the New World, countless millions were killed by...

In which John Green teaches you about what westerners call the middle ages and the lives of the aristocracy...in Japan. The Heian period in Japan lasted from 794CE to 1185CE, and it was an interesting time in Japan. Rather than being...

In which John Green teaches you about Iran's Revolutions. Yes, revolutions plural. What was the1979 Iranian Revolution about? It turns out, Iran has a pretty long history of unrest in order to put power in the hands of the people, and...

In which John Green teaches you about disease, and the effects that disease has had in human history. Disease has been with man since the beginning, and it has shaped the way humans operate in a lot of ways. John will teach you about the...

In which John Green teaches you about conflict in Israel and Palestine. This conflict is often cast as a long-term beef going back thousands of years, and rooted in a clash between religions. Well, that's not quite true. What is true...

In which John Green teaches you about the Holy Roman Empire by teaching you about Charles V. Charles Hapsburg was the holy Roman Emperor, but he was also the King of Spain. And the King of Germany. And the King of Italy and the Lord of...

In which John Green teaches you about water! So, we talk about resources a lot on Crash Course, and today is no exception. It turns out people can't live without water, which means it's absolutely necessary for civilization. Today John...

In which John Green teaches you about war! Specifically, John talks about whether humanity is naturally warlike, hard-wired to kill, or if perhaps war is a cultural construct. John will talk about the Hobbes versus Rousseau debate, the...

In which John Green teaches you about the Little Ice Age. The Little Ice Age was a period of global cooling that occurred from the 13th to the 19th centuries. This cooling was likely caused by a number of factors, including unusual solar...

We've been talking a lot about kings, and queens, and wars, and religious upheaval for most of this series, but let's take a moment to zoom out, and look at the ways that individuals' lives were changing in the time span we've covered so...

In which John Green teaches you about how Islam has interacted with politics during it's history, and how it continues to do so today. Islamist movements are in the news a lot lately, but how did that happen. John will point out that...

The Sahara is rather famously a desert, but it wasn't always that way. And during the time of lush green forests, there were plenty of people who lived there, but they've been hard to study. However, new genetic analysis has given us...

Soviet agronomist Nikolai Ivanovich Vavilov was obsessed with plants. Especially finding out where domesticated crops first came from. And out of his research came a proposal that certain crops, like rye and oats, were evolutionary...

In 1992, something unprecedented happened in Los Angeles: rival gang members negotiated a historic peace treaty, significantly reducing violence across the city. Aqeela Sherrills, one of the key negotiators of that treaty, continues to...

Common knowledge is the secret engine of social life, letting us coordinate everything from meet-ups to markets to international diplomacy. In this fascinating talk, experimental cognitive scientist Steven Pinker explores its momentous...

In a moment that stunned the world in 2019, the famed Notre-Dame in Paris went up in flames, threatening the future of the centuries-old Gothic treasure. Philippe Villeneuve, the chief architect of the cathedral’s restoration, recounts...

The journey the thunder beasts took to reach such mega proportions from such humble beginnings forces us to ask an important question, one that paleontologists have been asking for more than a century: from an evolutionary perspective,...

When exactly did we start drinking other things, and why? To find out, we have to look at the world’s oldest beverages – which might not be what you expect.

Where are all the east coast dinosaurs? Why don’t we find famous species like Triceratops in Central Park? Turns out, evolution and geology came together to make the east coast into an ancient lost world of weird dinosaurs.

In 2003, a fossil belonging to a mammaliaform was discovered in an ancient lakebed in what's now China. It was an almost complete skeleton the size of a platypus, a find that complicated the history of mammaliaforms. It painted a picture...

While the evolution of the butthole was a major breakthrough in animal development, its story might actually end with redefining what it means to have a butthole at all.

This is the hundred-year tale of how an unlikely bunch of bottom-dwelling marine critters helped reveal that ocean basins are basically reincarnated every few hundred million years.

After having solved the small matter of evolution by natural selection - becoming one of the most famous scientists in the world in the process - Charles Darwin turned his focus to a different personal obsession…