Around 45 BCE, silk was introduced to  Rome.

Depending on what route you take,   this luxurious fabric travelled over  6400 kilometers on its way from China   and likely would’ve changed many hands. It wasn’t long before spices, produce,  and other cloth was moving east to west,   south to north, and everywhere in  between all over Asia, the Mediterranean,   and North Africa -- which some stories say took  anywhere from several months to almost 10 years.   And the routes got more elaborate or  simple depending on who controlled them,   and what taxes and fees  traders were trying to avoid.

This collection of routes -- which thrived for  almost 1600 years -- became known as the Silk Road. But today they are more often called the  Silk Roads to acknowledge just how many routes,   people, and places were part of this network. And even today -- over 2000 years since silk  first appeared in Rome -- exploring the Silk  .

Roads can tell us a lot about how worldviews  and other ideas spread along those trade   routes and eventually influenced the beliefs  of billions of people through time and space. I’m Alizé Carrère, and this  is Crash Course Geography. INTRO.

In Cultural Geography, we’re specifically  interested in how and why culture changes.   1600 years of trading along the Silk Roads offers  lots of examples of how diffusion, or the spread   of ideas across space, happened as traders mingled  and left artifacts like maps and statues behind. Imagine those late nights as travelers  from all over the world were staying at an inn,   a monastery, or other lodging. Maybe after an evening meal, they’d share  folklore from their homelands.

These are   stories that were passed on, often by spoken-word,  that educate a community about their history. Or, maybe they’d skip the stories and go straight  to how they see current conditions in the world.   Either way -- and in other ways too! -- they’d  share a little bit about their worldview which   is a set of beliefs, morals, and attitudes  about the world and a person’s role in it. Our worldview is transmitted to us by a  community, but then shaped and changed by   our life experience.

It helps us answer questions  that come from our natural human curiosity like,   what is the meaning of life? How did  the universe form? What is my purpose?   What is Truth?

Is there banana in this soup? The way we approach these questions and the way we   develop and share knowledge is  a fundamental cultural trait,   one of those building blocks that make up  our unique cultural identity, like language. Specifically, a religion is a belief system and  set of practices that help a community define   what is acceptable.

Religions can be driven  by theology, or belief in a divine power,   but there are also belief systems  guided by morals and principles   without the presence of something beyond humans. Now I just want to take a moment to say  talking about culture is really hard.   If you're taking an AP test or an intro to  geography class, you might see some religions   put into categories that don't perfectly match how  they exist and are practiced in the world today.   And that makes being a human geographer  really hard, but also really exciting. People are complicated, and there's so much  nuance to what we're studying.

So we'll do our   best to explain the definitions we're using, the  time period we’re talking about, and why or how   certain religions fall into different categories.  But just remember, the lines are pretty blurry. Like in Malaysia we saw how belief systems can  literally imprint on a space as people travel,   just like we imagined with those late night  travellers. Which is eventually how we end   up with places of worship built with both  Chinese and European elements, or people   in Malaysia and Indonesia practicing the same  denomination of Islam as people in Saudi Arabia.

And to us geographers, the movement of people’s  beliefs and how they build their identity through   those beliefs can tell us a lot about the movement  of power, empire, and people around the planet. In fact, relics from the time of  the Silk Roads show belief systems   mingling and moving -- if you know where to look. Around 150 CE, Claudius Ptolemy, a Greek scholar  living in Alexandria, wrote a book that contained   what Europeans would eventually use to create  (what they thought was) the map of the world.

His descriptions of how to draw a 2 dimensional  map of our 3 dimensional world have been so   celebrated that Western geographers  sometimes call him the father of geography. Now we know that his map projections  were really amazing for the time,   but there were a lot of meaningful geographic  advances before his book and between when  . Ptolemy published his calculations and when  Byzantines rediscovered them 1,145 years later.

Ptolemy’s calculations are exciting because  they use latitude and longitude lines,   which we might take for granted now but are really  an amazing mathematical innovation. He’s also   credited for working out the rough boundaries  of land, even land he hadn’t seen before. And even though we don’t have any versions he  drew himself, the math behind the map tells us   about Ptolemy’s worldview.

Mapmakers before  Ptolemy had sized different countries based   on how important they were. So even though many  of his calculations were later proven incorrect,   Ptolemy introducing math  changed cartography forever. And to the careful geographic eye this map  also reveals a lot about the worldview of the   cartographer who later drew the map.

Like the way  “Ethiopia” is sort of all of Sub-Saharan Africa.   Or how it looks like people are  blowing the wind around the world,   which gives a slight nod to  cherubs and Greek mythology. Along the Silk Roads we’d also find maps  that reveal other belief systems and   multiple religious hearths, or places of origin,  from which different religions diffused out. Today, the former lands of the Silk  Roads are still known for a large   number of people practicing an ethnic religion,   which is one of the two broad categories  of faiths and includes religions that   are typically tied closely to a place or  group of people from a particular culture.

Like within ethnic religions there  are often animist traditions,   or ethnic religions that worship based on  the local environment. Animist traditions   often understand that non-humans in nature have  spiritual power to help, harm, and teach humans. Within geography, belief systems we’d  find on the Silk Roads like Shintoism,  .

Taoism, and Confucianism are often considered  ethnic religions because of how the cultural   mechanisms to teach the belief system are  woven into their place of origin. Like   Shinto shrines are very important areas for  worship and are rarely found outside Japan. That doesn’t mean those practices don’t  exist outside of those places and peoples   or that other places won’t be added as  the belief system changes over time.   It just means they’re usually closely associated  with one group of people or one place.

Now when a religion or belief system spreads  and becomes accessible to a wide part of the   population outside of its hearth, a religion  is said to be universal. In general, universal   religions are seen as ones that spread easily,  are easy for people in any location to convert to,   and don’t need a person to come from a particular  ethnic group to fully participate in that faith. “Ethnic” or “universal” are examples of  those messy categories we use to try and   understand religion. Buuuuut, it’s complicated.

Like as some people from what is now India moved  along the Silk Roads starting in the 4th century,   they would’ve brought their belief systems with  them. What originally developed in the Hindu   religious hearth was probably something called  Brahmanism. Then as people practiced this belief   system, it would’ve changed, eventually  becoming more recognizable as Hinduism,   which has inspired what are considered  distinctively Indian cultural traits.

But, those traits also can diffuse, often through  relocation diffusion which is one of the broad   categories of diffusion and is when people move  and take their beliefs. That ease of movement   occurs in part because this faith practice is  also able to incorporate a wide range of beliefs. So it’s common in geography texts to see Hinduism   put into the ethnic religion category  because it’s most accessible in India.   But Hinduism today has elements of both ethnic and  universal faiths and is a major world religion.

Faith leaders of all major religions would’ve   also had places called caravansaries for  travelers to rest along the Silk Roads. For example, there were several Buddhist  monasteries on the road connecting Bactria   to Taxila. While there was no fee for  lodging, travelers often would make a   donation as a sign of generosity.

In return,  the monks would impart spiritual guidance. So over time, some traders might’ve made a regular  habit of stopping to learn from particular monks,   and through that habit, followers of  Buddhism increased. This is an example   of a type of contagion diffusion,  or the spread of ideas from contact,   which is a type of expansion diffusion,  the other broad category of diffusion.

So maybe it's not a coincidence that a  majority of the faiths we'd describe as   "universal" can be traced to origins  along the Silk Roads, and that within   each of these broad religion groups, there are  hundreds of denominations and local practices. Today we can look back and see how other  ideas diffused along the Silk Roads too.   Throughout the Middle East and North Africa,  the cultural importance placed on education,   first from the Greeks, then Romans, then Muslims,  led to one of the oldest existing and currently   operating universities being established in Fez,  in what is now Morocco in the 9th century CE. Fez became a center of education, which, along  with the many large cities along the Silk Roads,   often had hierarchical diffusion, another  type of expansion diffusion that we see   when a prominent population  practices a cultural trait.   Slowly the idea spreads to smaller  towns and the surrounding area.

As a product of those learning systems,  by 1154 CE, there was a new map of the  . Silk Roads made by Muhammad al-Idrisi,  an Arab-Muslim geographer, traveler,   and scholar that came from the Almoravid empire  in what is now called Morocco. This map came from   firsthand reports of travelers and geographers  that worked for him, as well as his own research.

Artifacts like Al-Idrisi’s map leave behind  clues about how people interacted with and   saw the world, just like Ptolemy’s. This  map was notable because like many maps by   Muslim and Chinese cartographers, South was  oriented at the top of the map, not North. While there’s no definitive explanation for  why maps were oriented that way, by orienting   the map with South at the top of the page, the  Holy Land of Mecca is often central to the map.

Maps often reveal what was important  to the cartographers making them,   and in fact, the Islamic Holy Land  would have been important to many   people since it’s also holy to the other  Abrahamic Faiths, Christianity and Judaism. In 2020, the three major Abrahamic Faiths are  practiced by over half of the world’s population.   That huge spread has several reasons, but one  would be various types of expansion diffusion,   which is when a cultural trait develops  in a center, and then moves outward. Though the Middle East and North Africa  wasn’t the only site of significant diffusion.   By 1402 CE, what we now call Korea and China  became places of great cultural mixing,   especially along the trade routes between  present day India, Tibet, China, and Korea.

At that time, there was a Korean map called  the Gangnido that would’ve been used that’s   thought to have been completed with  the aid of Muslim and Chinese maps. And like the maps before it, the Gangnido  is significant because it shows a worldview   that’s centered on the homeland of  the cartographers, and is one of the   earliest maps to get the shape of Africa  and the Arabian Peninsula mostly correct. Today’s religious map shows a world full of unique  interpretations of morality and beliefs.

And this   map is deceiving -- remember, with a thematic map  like this, the nuance of the data is obscured. Like there are lots of cases of cultural  acculturation along the Silk Roads,   where people would pick and choose  different elements to combine.   Ultimately we end up with  something related, but different. In some of these cases, we end up  with faiths that combine the core   beliefs from two or more religions,  which are called Syncretic Religions.

And thematic maps can’t show this  complexity, the merging and overlap   of religions regionally, and that there are  multiple religions in each of these places. As we know, maps are often created from  the worldview of the cartographer and   can prioritize certain stories -- like where the  center of the world is -- or can minimize others,   like the location or prominence of ethnic faiths. But by comparing maps throughout history,   we can see that the Silk Roads played a major  role in facilitating the diffusion of knowledge,   both academic and religious, along with  the movement of goods like spices and silk.

Today, hundreds of years later, we still  feel the impact of the way knowledge has   developed -- like in the spices we use when  we cook, the cloth we see as beautiful,   and the traditions and rituals we practice.  All of these changed along the Silk Roads and   will continue to change as our cultures  share knowledge and make it their own. Thanks for watching this episode of Crash  Course Geography which is filmed at the Team  . Sandoval Pierce Studio and was made with the  help of all these nice people.

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