The Heart Sutra hardly fills a page, and yet it is the best known of the thousands of scriptures in the Buddhist Canon. Its fame, though, is relatively recent in terms of Buddhist history and didn't begin until a thousand years after the Buddha's Nirvana... Since then, the Heart Sutra has become the most popular of all Buddhist scriptures, and yet no one knows where it came from or who was responsible for its composition.

The oldest portions Perfection of Wisdom (Prajnaparamita) texts are considered to be among the earliest wisdom scriptures of the various movements in Indian Buddhism that came to be known as the Mahayana.  

Edward Conze identified four periods in the development of
the Prajnaparamita literature:

1. The elaboration of the basic text, referred to as the Perfection of Wisdom in 8000 Lines (ca. 100 B.C. to A.D. 100).

2. The expansion of the text - from this prototype there grew, through a process of interpolation, duplication, and iteration, the longer versions of the Prajnaparamita , such as those in 18,000, 25,000, and 100,000 lines (ca. A.D. 100 to 300).

3. The restatement of the doctrine in short sutras and verse
   summaries – including the Heart Sutra (ca. 300-500).

4. The period of tantric influence.

Although Conze placed the composition of the Heart Sutra in the third period,
at about A.D. 350, at this time our earliest record of the sutra is a Chinese translation from the first half of the third century and current thinking places the creation of the text in the second century.