The Mahavamsa is comprised of three parts, all written at different times in Sri Lankan history. The combined work, sometimes collectively referred to as the “Mahavamsa” provides an unbroken historical record of over two millennia and is considered the world’s longest continuous history. Buddhist monks of the Mahavihara maintained this Sri Lankan historical record starting from 3rd cent. B.C., somewhat similar to a modern-day diary. These records were combined and compiled into a single document in the 5th cent. CE by the great Buddhst elder Mahanama.
Earlier documents known as the “Dipavamsa” were also handed down and are much simpler with less information than the Mahavamsa, probably compiled relying on a text also used by Mahanama.
Overall, the Great Chronicle has over 200,000 words and about 960 pages. The first part (Chapters 1-37) is the Mahavamsa, the second part (Chapters 38-79) the Culavamsa Part 1, and the third and final part (Chapters 80-101) the Culavamsa Part 2.
The Dipavamsa is considered to have been compiled between A.D. 361, the year King Mahasena died, and 429, the year Buddhaghosa [the most famous commentator who compiled perhaps the most famous meditation instruction manual, The Path of Purification], who had come from India to live near the Mahavihara [the "Great Monastery," pictured at left] in Anuradhapura, began writing a commentary on the disciplinary rules (Samanta-pasadika).
(1) King Voharikatissa (A.D. 269-291): "Suppressing the Vetulya-doctrine, and keeping heretics in check by his minister Kapila, he made the true doctrine to shine forth in glory" (XXXVI. 41).
(2) King Gothabhaya (Meghavannabhaya, A.D. 309-322): "He seized bhikkhus dwelling in Abhayagiri Monastery, 60 in number, who had turned to the Vetulya-doctrine [Mahayana Buddhism] and were like a thorn in the doctrine of the Buddha, and when he had excommunicated them, he banished them to the further coast" (XXXVI. 111,112).
In A.D. 410-411, Faxian, a Chinese monk, who had left China in 399 to seek Vinaya texts [books explaining the disciplinary rules and their origins], and who had made long travels by land, stayed in Sri Lanka for two years. He then returned by sea with Buddhist texts on board a ship, and back home wrote down a detailed record of the travels for himself (Taisho Tripitaka Vol. 51, No. 2085). According to this record, five thousand monks in Anuradhapura were abiding in the Abhayagiri Monastery, and for ninety days annually the Buddha's teeth were carried from the Temple of the Tooth to the Abhayagiri Monastery to receive people's offerings. In the Mahavihara Temple Complex three-thousand monks were abiding.