Although the teachings that make up the Prajnaparamita are thought to have originated in Southern India in the first or second century b.c., the Heart Sutra was most likely composed during the first century A.D. further north, in the territories under the control of the Kushans: in the area that is now Afghanistan, Pakistan, Uzbekistan or India's Uttar Pradesh.
Although Buddhist monks began arriving in China as early as the first century B.C., it wasn't until the height of the Kushan Empire, or around A.D. 150 that they began translating the texts they brought with them or that others brought to China on their behalf. The Yueh-chih monk Chih-lou-chia-ch'an is said to have begun working in the Han dynasty capital of Loyang around this time on some of the earliest known scriptures of Mahayana Buddhism, including the Perfection of Wisdom in Eight Thousand Lines. Between A.D. 2OO and 25O, his disciple's disciple, Chih-ch'ien, also translated a number of Mahayana scriptures, including a second rendition of the Perfection of Wisdom in Eight Thousand Lines and the first translation of the Heart Sutra, which he titled the Prajna-paramita Dharani.
This was followed by a second version by Kumarajiva around A.D. 400.
A key player in the story of the Heart Sutra’s journey to the 21st century is a young early 7th century monk named Hsuan-tsang.
While still in his teens, this novice befriended a man who was impoverished and ill, and the man, in turn, taught him the words of the Heart Sutra. Not long afterward, the novice was ordained a monk, and several years later, in 629, he embarked on one of the great journeys of Chinese history.
Hsuan-tsang set out on the Silk Road for India in search of answers to questions concerning the Buddha's teaching that this world is nothing but mind. In the course of his journey, Hsuan-tsang is said to have traveled 10,000 miles—west across the Taklamakan Desert to Samarkand, south over the Hindu Kush to the Buddhist center of Taxila, and down the Ganges into India and back again. And time and again, he turned to the Heart Sutra to ward off demons, dust storms, and bandits. When he finally returned to China in 645, he was welcomed back by the emperor, and stories about the power of the Heart Sutra began making the rounds.
Hsuan-tsang also produced his own translation of the Heart Sutra in 649, and it wasn't long afterward that the first commentaries began appearing, as his fellow monks realized that not only was this a scripture of great power, but its summary of Buddhist teaching provided the perfect platform from which to offer their own interpretations of the Dharma.