WATCH: Unit 1 Overview

Anyone who knows, and knows that he knows, Makes the steed of intelligence leap over the vault of heaven. Anyone who does not know, but knows that he does not know, Can bring his lame little donkey to the destination nonetheless. Anyone who does not know, and does not know that he does not know Is stuck for ever in double ignorance. That’s a poem attributed to the thirteenth- century Persian scholar, Nasir al-Din al-Tusi. You’re going to encounter him—and a lot of other people, events, religions, empires, and other stuff—in this unit and in this course.  After all, we’ve got 800 years and one whole world to learn about! Now, if you’re like me, you don’t know everything. But like the poem said, that’s not a big deal. This is only Unit 1, and we’re just getting started. Also if you’re like me, you know that you don’t know everything. So, let’s follow al-Tusi’s advice, hop on our little donkey and head out to our destination: the world from 1200 to 1450 CE. First, let’s address one thing you probably don’t know: Who’s Nasir al-Din al-Tusi, and why did I am talking about him? Well, have you ever wondered how we know that the Earth revolves around the Sun, or why you have to go to chemistry and math class? Or how we know what makes our eyes work, and how to make glasses? Part of the answer to that is: Because of Islamic scholars like al-Tusi. He was one of the many scholars working during what historians call the “Islamic Golden Age.” It lasted from the eighth century all the way to the fourteenth. During this period, scholars like al-Tusi made incredible advances in fields like astronomy, mathematics, medicine, literature, and chemistry. Their progress in these fields was so remarkable that much of our modern scientific knowledge is descended from their work. Exploring the histories of Al-Tusi and the Islamic Golden Age can help us understand some important connections between the themes of Governance, Technology and Innovation, and Cultural Developments and Interactions. How? Well, my fellow donkey riders, let’s find out together. Hi, I'm Rachel Hansen and this is Unit 1: The Global  Tapestry 1200-1450 CE. In each unit of this course you'll see either me or my fellow teacher John Arthur in one of these thematic overview videos. You've probably met us before, we were in the themes overview video at the start of the course, so we're pretty famous. In that video we introduced the six themes of the course. Here in these unit overview videos, we'll show you how to use those themes to explore the big narratives of world history from 1200 CE to the  present In each video we'll use one historical example like al-Tusi and the Islamic Golden Age to help illustrate something about our six themes. But we'll also provide a quick overview of  the big historical developments in each unit   to help you develop your narrative of the  past 800 years of history.   Let's begin where this course does, in the year 1200 CE.   There's nothing particularly special about that year. So if you're asking, "Why start a course in  1200?" it's a fair question. Some world history courses begin in 1500, when the two biggest land masses of the world, Afro-Eurasia and the Americas,  connected into the first sustained global system. Other courses start much earlier, but we think 1200 makes sense. Here's why: Starting our global story in 1200 allows us to explore something important, a rich tapestry of countless diverse  communities stretching across our globe. Many of these communities were  disconnected from those in distant places. The year 1200 shows us the world before the great  linkages and accelerations of the modern era. The world from 1200 to 1450 was very different from our own, but it was a world on the verge of great changes. We think that you'll be able to understand those changes better if you understand what the world looked like before they started. Because Afro-Eurasia, the Americas, and the land  masses of Oceania were not yet connected in 1200, the world in Unit 1 was a world of astounding diversity. The ways that people lived, their beliefs, foods, fashions, and so many other aspects of life wove a diverse global tapestry. So, in Unit 1 we'll hop from one  region of the world to the next,   exploring many ways that societies  governed and organized themselves as well as some of the shared culture that  crossed physical and political barriers. We'll ask how states formed and how they  collapsed in this period.    Belief systems like Buddhism, Christianity and Islam spread creating similarities across borders. Yet, in each instance local conditions and distance  ensured great variation in experiences. As a result, a Polynesian sailor in the Pacific Ocean lived  in a very different world from an Aztec merchant, a Chinese bureaucrat, a scholar in Timbuktu, or a French peasant. To be sure there, were long distance networks linking humanity. Still, large regions of the world remain disconnected from others. In this unit, we'll compare the different  ways that human societies govern themselves. Our focus will be on how states  expanded, governed, and collapsed. But we'll also see how governing strategies  interacted with technological, economic, social, and cultural developments. As a result, we'll see some very different governing strategies emerge, but we'll also see similarities between  regions and continuity over time. Here's an example of what we're talking about: Nasir al-Din al-Tusi was born in 1201 CE. He witnessed some of the transformative  events you'll encounter in this unit, such as the Mongol invasions of Persia.  In fact, one Mongol khan hired al-Tusi as an advisor and funded a grand astronomical observatory  in which al-Tusi could study the stars. al-Tusi wrote hundreds of books on topics like  mathematics, astronomy, philosophy, and religion. While he worked at the observatory, he made  detailed charts of planetary movements.  His work improved on the mathematical  models of the ancient Greek astronomer, Ptolemy.   One of al-Tusi's greatest achievements  is called the Tusi Couple, a mathematical model to explain the orbits of the planets. Some historians claim that Nicolas Copernicus used al-Tusi's work 300 years later, when he developed his heliocentric  model, which argued that the earth orbited the sun. During the Islamic Golden Age, centuries of scholars developed new knowledge and innovations in many different fields.  And, if you're familiar with the names Aristotle, Plato, or Socrates, you should thank the Islamic Golden Age.   It was Islamic scholars who preserved, translated,  and improved on the ideas of the ancient Greeks. And, who do we have to thank for the work of these scholars?   Well, just as today's great thinkers are granted funding by powerful institutions, the Islamic Golden Age's Sultans, Caliphs, Khans, and other rulers valued and paid for all this innovation. Science ain't cheap. So, why would rulers fund something like astronomy? I mean, they weren't planning to launch any rockets to the moon. But astronomy, like medicine, history, architecture,  mathematics, and the other forms of knowledge   funded by Islamic empires, benefited the state. For example, by measuring the movement of the sun, moon, and the stars, Muslim scientists helped determine the correct times for daily prayers, set the dates for the lunar calendar, and precisely calculated the direction of Mecca from any location. This knowledge was valuable to political  and religious leaders in the Islamic world. And, as for al-Tusi, the Mongol khans believed  that reading the stars could predict the future   and provide guidance on government policies. Nasir al-Din al-Tusi and the other scholars of the Islamic Golden Age provide us a window into the world of 1200 to 1450, a world of changes and continuities similarities and differences. It highlights some important linkages between the governance, cultural developments and  interactions, and technology and innovation themes that you'll encounter in this unit.