For nearly 1,000 years, much of Southeast Asia followed religions that we think of as exclusively or originally ‘Indian’. The colossal temple of Angkor Wat in Krong Siem Reap, Cambodia — beautifully described by William Dalrymple in a recent article in Financial Times — and the overgrown Angkor ruins, with their serene depictions of Hindu deities, are often held up as proof that India colonised, inspired or influenced Southeast Asia in some way.
Like with all things medieval, it turns out that the truth is far stranger than modern notions. It is certainly beyond dispute that for many centuries — starting from around the 8th century CE all the way up to the 15th — the religious culture of Cambodia was predominantly Shaivite. But the process by which it became Shaivite is astonishing: Contrary to what we may think, it involves active conversion by Hindu preachers, market forces emerging from Cambodian courts, Indians emigrating in search of greener pastures, and a considerable degree of intelligence and selectivity in how Cambodia interacted with ‘Indian’ ideas.
Roughly around the second century CE, legend holds that the corpse of a young man in Karohana (present-day Karvan), Gujarat, was reanimated. This man, Lakulisha, then went about preaching a Shaiva doctrine revolving around asceticism and meditative practice to inculcate magical powers. And thus, the sect known as the Pashupatas was born. It would grow to become one of the most influential and widespread sects of all early medieval schools of Shaivism.
In full: https://theprint.in/opinion/indias-hindu-preachers-how-shaiva-monks-converted-cambodia/1097764/