In line with many Buddhist tantras in addition to classic Tibetan Buddhist resources, the tantras and also the Vajrayana was taught with the Buddha Shakyamuni, but only to some persons. There are various tales and versions of how the tantras were disseminated. Monks attending the 2003 Kalachakra empowerment in Bodhgaya, https://kylerarfpf.blogoscience.com/39424339/goldie-madan-is-world-famous-aghori-an-overview