Graham Shaw, the deputy director of the Library's Oriental and India Office Collections, said the fragments are several centuries older than previously known Buddhist manuscripts.
They were bought for an undisclosed amount from a British dealer, and contain parts of about 25 texts from the Gandhari Buddhist civilisation which flourished in what is now eastern Afghanistan, using a script which disappeared in the fifth century AD.
Though Gautama Buddha died in 486BC, after founding a religion which is still one of the world's most important, none of his teachings were written down for at least 300 years after his death.
The problem for later scholars is that Buddhism, though triumphant in northern India by the third century BC, later vanished from there, under the twin pressures of a Hindu renaissance and Muslim hostility.
Though it is believed that many Buddhist texts are early, the manuscripts that have survived are almost all translations into the languages of neighbouring countries where Buddhism still flourishes.
Lance Cousins, a former head of Buddhist studies at Manchester University, said yesterday that oral transmission within monasteries could be more a more reliable way to preserve a text than copying manuscripts, a notoriously error-prone process.
Mr Shaw said that the manuscripts he had bought had formed part of a much larger collection. Not all had been identified: "We don't have any one complete text, but it looks as if we have samples from a range of Buddhist scriptures.
"We have already identified some technical treatises and philosophical expositions. We also have some more popular interpretations of Buddhist teachings in poetical form, that were meant for a mass audience - the 'songs of Lake Anavatapta' on the shores of the lake in high Himalayas, in which each member of the Buddha's circle recounts the deeds in former lives which have made him the man he is."
However, he believed that some of the texts not yet identified might contain entirely new stories or teachings. Previous to this find, most of the oldest Buddhist manuscripts were Chinese, Tibetan, or Nepalese.
Himalayan monasteries, which had the advantage of cold, dry air could preserve manuscripts for centuries. Older Buddhist engravings had also appeared in central Asia.
Southern Buddhism, with a hotter, damper climate, and palm leaves instead of birch-bark to write on has no manuscripts older than the ninth century.Reuse content