The role of Greek Buddhist monks in the development of the Buddhist faith under the patronage of Emperor Ashoka around 260 BCE and subsequently during the reign of the Indo-Greek king Menander (r. 165/155–130 BCE) is described in the Mahavamsa, an important non-canonical Theravada Buddhist historical text compiled in Sri Lanka in the 6th century in the Pali language. The Mahavamsa or "Great Chronicle" covers the history of Buddhism from the 6th century BCE to the 4th century CE. It was written in the 6th century by the monk Mahanama, brother of King Dhatusena of Anuradhapura, and heavily relied on the Dipavamsa or "Island Chronicle" written five centuries earlier. Background Emperor Ashoka convened the third Buddhist council around 250 BCE at Pāṭaliputra (today's Patna). It was held by the monk Moggaliputta. The Pāli Canon, which consists of the Theravada texts of reference and considered to be directly transmitted from the Buddha, was formalized at that time. It is known as the Tipiṭaka or "Three Baskets" and contains doctrine (Sutta Pitaka), monastic discipline (Vinaya Pitaka) and a compendium of philosophy (the Abhidhamma Pitaka). Another objective of the council was to reconcile the different schools of Buddhism and to purify Buddhism, particularly from opportunistic factions which had been attracted by the royal patronage. Finally, the council also reported on the proselytizing efforts of Ashoka, who sought to expand the Buddhist faith throughout Asia and as far as the Mediterranean Basin. The contemporary stone inscriptions of the Edicts of Ashoka also relate this activity in detail. Following these efforts, the Buddhist faith seems to have expanded among Greek communities under the rule of Ashoka, and tens of thousands were converted. About 50 years laters, the Greco-Bactrian Kingdom invaded North India as far as Pāṭaliputra and founded the Indo-Greek Kingdom. Buddhism flourished under the Indo-Greek kings, and it has been suggested that their invasion of India was intended to show their support for the Maurya Empire and to protect Buddhism from the religious persecutions of the new Shunga Empire (185–73 BCE). Greek Buddhist monks continued to play a key role during the time of Menander, as far as Sri Lanka. Greek monks under Ashoka According to Edicts of Ashoka, Greek populations (generally described in ancient times throughout the Classical world as Yona, Yojanas or Yavanas, lit. "Ionians" ) were under his rule in northwestern India. Far from just being on the receiving end of