Origin and Development of Vajrayana

[Astus]

I'm looking for sources on the history of Vajrayana, including its origins and development in India and Tibet. I'm not familiar with the area, so anything may come. I already know of Sam van Schaik's EarlyTibet blog and I have Ronald M. Davidson's book "Indian Esoteric Buddhism: A Social History of the Tantric Movement", but basically that's all. I'd especially appreciate good summaries and enlightening essays, but as I've said, any good text is OK.

Note: it is not the religious history I'm interested in but the latest academic research.

[Mr. G]

I'm a non-academic so I'm not familiar with the latest teachings. However, I really like the chapter on tantra written by Anthony Tribe in Paul William's book "Buddhist Thought: A Complete Introduction to the Indian Tradition".

I liked both of Ronald Davidson's books too.

[Astus]

It indeed has a good summary, thanks for the tip, but only a really short one.