I very much enjoyed this lecture by Alexander Wynne, which covers some of the recent scholarship on the origins and historical fate of Buddhism in India, in relation to Brahmanism. He discusses Johannes Bronkhorst’s idea, developed in three recent books, that Buddhism arose in the non-vedic culture of a region of India he calls “Greater Maghada.” Wynne seems to endorse much of Bronkhorst’s argument, but also offers some evidence that Brahmanism was a greater cultural presence in parts of the Buddha’s own sphere of activity than Bronkhorst allows, and disagrees with Bronkhorst on the dating of the important Bṛhadāraṇyaka Upanishad.
He also discusses the archaeologist Giovanni Verardi’s recent book Hardships and Downfall of Buddhism in India, a book I haven’t read. I now think I have to read this book! It offers a new hypothesis about the causes of the disappearance of Buddhism from India. Rather than painting a generally peaceful picture of the gradual withering away of Buddhism, and absorption into Hinduism, prior to the Muslim invasions, Verardi apparently proposes that the period of the decline of Buddhism was one of great violence, in which the imposition of Varna culture was carried out with brutal persecution and destruction - effectively a religious war that the Buddhists lost.
Note that there are slides on the web page. It’s good to have them before you while listening, because Wynne refers to the quotes and images they contain a few times.