After about 500 CE, Buddhism showed signs of waning in India,
becoming nearly extinct after about 1200 CE. This was partially
due to Muslim invasions and partially due to Hinduism's revival
movements such as Advaita and the rise of the bhakti movement.
Elements of Buddhism have remained within India to the current
day: the Bauls of Bengal have a syncretic set of practices with
strong emphasis on many Buddhist tantric and philosophic concepts.
Other areas of India have never parted from Buddhism, including
Ladakh and other areas bordering the Tibetan, Nepali and Bhutanese
borders.
Buddhism also remained in the rest of the world although in Central
Asia and later Indonesia it was mostly replaced by Islam. In China
and Japan, it adopted aspects of the native beliefs of Confucianism,
Taoism and Shinto respectively. In Tibet, the Tantric Vajrayana
lineage was preserved after it disappeared in India.