Railing fragment: Adoration of the Buddha as a fiery pillar, India, 3rd century, limestone – Prince Siddhartha Gautama, later known as Buddha, was born at the foothills of the Himalayas around 5th century BC. Abandoning a life of luxury, his journey from asceticism to enlightenment captured the imagination of thousands across India.
"Buddhism at the time was a bit of a revolt to the caste system of Hinduism," says McCullough. "It was more of an all inclusive religion so it was popular."
At first Buddha was only represented with symbols like the fiery pillar in this fragment found in Amaravati in the Indian state of Andhra Pradesh.
"It's an ancient idea that God is a pillar of the universe that holds it together," says McCullough referring to a Vedic story about the god Shiva. "At that time it obviously wasn't important to have a Buddha in human form."
At the bottom of the pillar are footprints indicating Buddha's presence.
Relief of Buddha's descent from the Trayastrimsha Heaven, Gandhara, 3rd or 4th century, schist – By the first and second century AD, images of Buddha in a human form infiltrated the art scene.
"Buddhism starts to become a bit more of a religion in terms of worshiping," says McCullough. "It's considered important to have an object of actual veneration to look at."
This relief is part of a series of images chronicling the life of Buddha. He appears in the central panel descending from a staircase flanked by Vedic gods Brahma and Indra.
"Buddha had gone to heaven to preach to all the other gods and his mother. It's a way of showing how important he is in the universe," she says. "He is one of the gods now."
Model stupa, Gandhara, 3rd or 4th century, schist – Cremated relics of the Buddha such as his tooth, strands of his hair or bones were scattered in different dome-shaped structures called stupas. Inspired by simple burial mounds, these were at the heart of the Buddhist landscape that spread across India.
Stupas were decorated with stories of the Buddha's path.
"You would contemplate the images and think about your own path to enlightenment," says McCullough.
Pilgrims and merchants flocked to these sites in the hope of gaining religious merit.
This is an architectural prototype of a stupa. The circular lid could be removed to place a relic inside. Intricately carved, the bottom tier shows the Buddha deep in meditation with attendants on either side.
Head of a bodhisattva, Gandhara, around 4th century, terracotta – Soon Mahayana Buddhism becomes increasingly popular as it suggests that everyone can achieve salvation.
"It's much more Buddhism for the layperson not just the monk who can live a monastic life like the Buddha," says McCullough.
Bodhisattva figures like this start to proliferate and help to make the religion more accessible. Intercessors of sorts, Bodhisattvas have achieved enlightenment like Buddha but they forgo entering nirvana and stay in the physical world to guide others.
This striking bodhisattva with a mop of thick curls was shares similarities with classical Roman sculptures. It was found in Gandhara, an area in present-day Pakistan and Afghanistan. Alexander the Great conquered the region around 330 B.C and so Greco-Roman motifs filtered into Buddhist imagery over the years. The small indent in the figure's forehead would have been inlaid with a jewel. Bodhisattvas wore jewelry setting them apart from Buddha.
Buddha, China, Northern Qi dynasty (550--577), limestone with traces of paint – This elegant limestone figure of Buddha clad in delicately carved cloth is likely to have been surrounded with other sculptures illustrating his life.
"It shows him renouncing worldly wealth and wearing an ascetic pauper's robe," says McCullough. "You are trying to follow his path so his life stories are very important. Like Christianity, paintings and sculptures teach illiterate people about religion. They aren't reading about it."
Torso of a bodhisattva, China, 7th or 8th century (Tang dynasty), stone – This graceful bodhisattva figure would have likely sat in a niche in a cave temple. Teeming with paintings and sculptures, caves were like magnificent galleries of ancient Buddhist art.
"It is thought that [the Chinese] got the idea from India where they created caves since ancient times," says McCullough. "Monks have lived in caves forever. Mountains and caves are considered holy places so it makes sense."
The shape of the bodhisattva's torso as well as the style of the jewelry and flowing garment resting on his hips also suggest the ongoing influence of Indian art.
Bodhisattva, China, 7th or 8th century (Tang dynasty), limestone – "Buddhism had an open-minded attitude," says Dr. Guang Xing. "It absorbed and upheld local cultures and traditions and even local gods."
During the Tang Dynasty, for instance, the male bodhisattva of compassion (Avalokiteshvara) was transformed into a female (Guanyin).
This elaborate sculpture may be a depiction of the Chinese bodhisattva Guanyin. The upper class became a major force behind Buddhism which explains why she is dressed a court lady. It was believed that by creating Buddhist images, devotees could eventually shorten the cycle of birth and death and relieve suffering.
Lokeshvara, Champa (central Vietnam), 9th century, gold and silver – By the 9th century, Buddhism had made serious inroads into Southeast Asia. The support of local rulers was central to the spread of the religion.
Facial features of Buddhist sculptures changed over time and across regions to appear like the people who created them, which was likely the case here. This resplendent gold and silver sculpture from Champa in Central Vietnam depicts Lokeshvara (Lord of the World) a bodhisattva known for compassion and supernatural powers.
Avalokiteshvara, Dali Kingdom (Yunnan province, China), around 10th century, gilded bronze – The Buddhist religion evolved over the decades accumulating a large pantheon of deities and increasingly elaborate rituals. Between the 10th and 13th centuries, the Dali Kingdom in the present-day Yunnan province became a center for tantric Buddhism, an esoteric branch of the religion. It is clear that by the time it arrived here, the Buddhist faith had journeyed far from its simple roots.
This is a rare form of Avalokiteshvara, the bodhisattva of Compassion. He wears an ornate headdress laden with several Buddhas and has 34 arms clutching various symbols.
Unlike religions that used force to convert people, Buddhism coexisted harmoniously with the beliefs of various countries.
"Buddhism assimilated to such an extent that it assumed the role of protector of the local cultures, rather than destroyer," says Dr. Guang Xing. "As a result, Buddhism gradually became part of the local tradition so much that one can never separate them."