Introduction

Imagine you’re a young Indian prince living in the sixth-century BCE. You have every material thing you could want in life. Soon, you will inherit your family’s wealth and become a powerful warrior prince. But one day, you pop your head out of the palace and see that the world can be a pretty rough place for people who aren’t rich princes. What do you do? Well, if you’re Siddhartha Gautama (563–483 BCE), you renounce your titles and worldly possessions and begin wandering the countryside, begging for food and living the life of an ascetic—a person who lives a disciplined life by refusing to indulge in luxuries like ice cream, alcohol, and comfortable mattresses. As he adopted this lifestyle, Siddhartha began preaching a new belief system, and people started calling him “the Buddha.” His teachings became the foundation of Buddhism.

But this isn’t the story of one guy. The story of Buddhism is as much about the spread of Buddhism as its origins and teachings. The Buddha’s simple teachings quickly spread from India across Asia and beyond. As it traveled along trade networks, Buddhism touched the lives of millions of people. But Buddhism itself changed as it moved. In some places, like China, powerful leaders and movements adopted Buddhism, transforming it into one of the world’s major belief systems.

Origins

In the sixth century BCE, India was changing. After centuries of conquest, the Aryan people¹ had established new kingdoms, cities were growing again, and trade flourished in India’s ports and along its roads. But this was also a time of religious change across the ancient world.² The Aryan conquests of India introduced a new belief system called Brahmanism. Brahmanism was based on the Vedic texts and was dominated by a priestly class of brahmins. Brahmanism brought the caste system to India, which divided all people into a strict social hierarchy.

Both Hinduism and Buddhism emerged from this earlier belief system. But while Hinduism formalized elements of Brahmanism, such as the caste system and the divinity of the Vedas, Buddhism rejected many elements of the old religion. Buddhist beliefs challenged the social structure that gave priests special access to spiritual life. Instead, Buddhism suggested that anyone could gain salvation and wisdom by letting go of desire. In this way, Buddhist teachings rejected the caste system and challenged the existing social order.

Calculus of enlightenment

This article began by asking what you would have done in Siddhartha’s place. You probably had a different answer than he did. Maybe you enjoy ice cream and mattresses. And that’s okay. Not every convert to Buddhism was forced to adopt an extreme ascetic lifestyle. Buddhism offered believers a “middle path,” which was guided by the principles the Buddha had gained back when he was the young prince Siddhartha. According to Buddhist sources, Siddhartha had been meditating under a tree near the Ganges River when he had a spiritual epiphany (breakthrough). This epiphany revealed to him truths about the universe. He called these the “Four Noble Truths”:

1. life is suffering
2. suffering comes from desire
3. one must limit desire to limit suffering
4. to limit suffering, one must follow the “Eightfold Path”.

Four truths? Eight paths? This is starting to sound like math. Don’t worry. Math is suffering. This is not math. Here’s a primary source to prove it. The Pali Canon, an early text of Buddha’s teachings, describes the Eightfold Path like this:

And what is that ancient path, that ancient road? It is just this Noble Eightfold Path: that is, [1] right view, [2] right intention, [3] right speech, [4] right action, [5] right livelihood, [6] right effort, [7] right mindfulness, [8] right concentration. I followed that path and by doing so I have directly known aging-and-death, its origin, its cessation, and the way leading to its cessation [end]. I have directly known birth…existence…clinging…craving… feeling…contact…the six sense bases…name-and-form…consciousness…volitional formations [desires], their origin, their cessation, and the way leading to their cessation. (Gautama, 69).

Buddhism teaches that by controlling desire and limiting suffering, this path could lead a person to spiritual enlightenment. But the road to enlightenment was not easy. The Eightfold Path required a great deal of self-sacrifice and dedication. The women and men who followed this path often adopted a monastic way of life, leaving behind worldly affairs and devoting their lives to attaining spiritual enlightenment. This usually meant becoming monks or nuns and taking vows of celibacy and poverty, meditating, and abstaining from violence.

Buddhism and social change

Buddhist beliefs might have focused on individual enlightenment, but they had important social consequences. Buddhism challenged the structure of Indian society, where Brahmins had authority and status. It also challenged the caste system more broadly, because enlightenment was not limited to those of upper castes. Buddhism also welcomed women into monastic life, providing roles outside of the home. These differences made Buddhism appeal to many in the lower castes of Indian society.

As mentioned above, the road to enlightenment was difficult, and—probably like you—most people were unable or unwilling to abandon their families and possessions for a life of spiritual devotion. Most people who chose lives as monks or nuns did so because they could afford it. Laborers and servants, for example, could not simply abandon their livelihoods and retreat into spiritual contemplation.

But Buddhism was flexible. As it spread, new versions emerged to meet the different needs of converts. For example, Mahayana Buddhism, which means “the great vehicle,” allowed people to strive toward enlightenment even if they couldn’t become monks. Mahayana Buddhism grew into the most widespread form of Buddhism in the world. Buddhism’s rejection of the caste system and the flexibility of its “middle path” is what helped it spread across Asia.

From one Buddha to many Buddhisms

Though Buddhist beliefs originated in India, they spread quickly. Buddhism moved through trade networks, traveling on Silk Road caravans through Central Asia to China and aboard merchant ships to Southeast Asia. Buddhism also got some help from powerful leaders. Emperor Ashoka, who ruled the Mauryan Empire in India from 268 to 232 BCE, used his power and conquests to spread Buddhism through India and beyond. He sent missionaries from his empire into the surrounding regions, including Central Asia, Southeast Asia and Sri Lanka.

A big part of Buddhism’s success outside India was its ability to accommodate local beliefs. As it spread, Buddhism changed, blending with elements of different belief systems, a process known as “syncretism.” For example, Buddhist ideas blended with Confucian and Daoist beliefs in China, where concepts like ancestor veneration (honor) and filial piety (honoring elders³) became part of Buddhism. Another example is Greco-Buddhism. Descendants of Alexander the Great’s empire still lived in Central Asia, and when they converted to Buddhism, they blended it with elements of Greek culture. In some places, the Buddha came to be regarded as a deity, and new Buddhas were added to the pantheon, though these were not part of the original belief system.

After reaching China, Buddhism began to expand during the third century CE. An age of political upheaval followed the collapse of the Han Dynasty in 220 CE. This collapse of political authority meant many people sought meaning in new kinds of communities. For many, Buddhism offered a fresh start as the old order collapsed. Chinese rulers began using Buddhism to unite their people. From China, Buddhism spread to Korea and Japan. There too, Buddhism blended with local practices. Buddhist monks in Japan even became caretakers for Shinto shrines and participated in Shinto rituals.

Why did Buddhism spread around the world? First, it offered a universalist message: that every individual could attain enlightenment by following its teachings. This message appealed to those, like women and peasants, who were marginalized in society. Second, Buddhism was missionary and had several powerful political supporters. Buddhists believed that their message could and should be spread to everyone and anyone. Emperor Ashoka was the first ruler to encourage Buddhist missionaries to travel abroad, and later Chinese rulers sought to spread Buddhism as a way to build their own power and influence. Finally, Buddhism was a flexible belief system, capable of adapting and changing to fit very different places and people.

Though it is one of the largest belief systems in the world, with about 500 million followers today, Buddhism is not singular. It has taken on many forms in many places. From northern India, where it originated, Buddhism traveled along trade networks to Central Asia, China, Korea, Japan, and beyond. And though it originated and spread in India, Buddhism gradually became less popular there. In countries like Sri Lanka, Thailand, Myanmar, and Cambodia, Buddhism is today the dominant belief system. Wherever it went, Buddhism changed how communities were organized. It challenged social hierarchy, created opportunities for women, and gave individuals of all classes a role in spiritual practice. But as Buddhism changed each new society it touched, so too did Buddhism change. Indeed, it was Buddhism’s ability to adapt to new contexts that allowed it to spread so far.

1 The Aryans were warrior pastoralists from northern India who conquered much of India between 1500 and 500 BCE. They spoke Sanskrit, which is an Indo-European language related to Persian and even (distantly) to English.

2 This period also saw the rise of Confucius in China, Zoroastrianism in Persia, Greek philosophers, and the Hebrew prophets.

3 Yes, these terms can seem like synonyms, but basically ancestors are the elders who are no longer living, so there are a lot more of them. Filial is about the child/parent relationship. Piety usually means religious devotion, but in this context is more about honor, respect and obedience, and would include living parents, grandparents, great-grandparents, etc.