Succeeding kingdoms of Sri Lanka would maintain many Buddhist schools and monasteries and support the propagation of Buddhism into other countries in Southeast Asia. Sri Lankan Bhikkhus studied in India's famous ancient Buddhist University of Nalanda, which was destroyed by Bakhtiyar Khilji. It is probable that many of the scriptures from Nalanda are preserved in Sri Lanka's many monasteries and that the written form of the Tripiṭaka, including Sinhalese Buddhist literature, were part of the University of Nalanda. In 245 BCE, bhikkhuni Sanghamitta arrived with the Jaya Sri Maha Bodhi tree, which is considered to be a sapling from the historical Bodhi Tree under which Gautama Buddha became enlightened. It is considered the oldest human-planted tree (with a continuous historical record) in the world. (Bodhivamsa)