The story begins with a botanist. At the end of the 18th century, a Scottish doctor named Francis Buchanan was employed to carry out surveys of Burma and Nepal, neither of them with ease, the latter with great difficulty, while on missions to those countries. While he was engaged on this, he obtained glimpses of a new religion.
It was a new religion to the British, employees of the Honorable East India Company (EICo), but an old one to the subcontinent where it had been born. Its fate was curious: Like Christianity, this faith had faded from its land of origin, but been taken up with enthusiasm in surrounding countries, and extended its influence, in varying forms, over most of a continent. It was now about to be rediscovered.
"Discovered," in this context, means by Europeans and the Western world. This faith had not vanished in the many lands where it continued to be practiced, but the European preoccupation with Islam had long obscured knowledge of anything preceding or beyond that. The new EICo recruits, explains Charles Allen, were only familiar with the East through classical accounts, which did not allude to this religion.