The Avatamsaka Sutra did not arrive as a single composition. Several of its constituent parts circulated independently in India and Central Asia before being drawn together into the vast compilation known today, among them the Dasabhumika Sutra, an account of the ten stages of the bodhisattva path, and the Gandavyuha Sutra, the pilgrimage of the youth Sudhana through fifty three teachers in search of enlightenment, both of which continued to be read and translated as standalone texts even after their incorporation into the larger whole.
No Sanskrit manuscript of the complete sutra survives, and scholars generally place its assembly in Central Asia, possibly in the Khotan region along the Silk Road, sometime in the third or fourth century of the common era. It reached China in stages, most consequentially in a sixty fascicle translation completed by Buddhabhadra in the early fifth century and a fuller eighty fascicle translation by Siksananda at the end of the seventh century, commissioned under the patronage of Empress Wu Zetian, with a later fortieth chapter translation by Prajna adding an expanded version of the Gandavyuha section alone.
Paul Williams's survey of Mahayana doctrine treats this layered, composite history as characteristic of how the largest Mahayana sutras took shape, growing by accretion around an expanding core rather than being composed at one sitting by one hand, and the Avatamsaka is among the clearest surviving examples of the pattern because its formerly independent pieces are still identifiable within it.