Name the oldest local literary source in srilanka

 SRI LANKA'S HISTORICAL AND CULTURAL HERITAGE covers more than 2,000 years. Known as Lanka--the "resplendent land"--in the ancient Indian epic Ramayana, the island has numerous other references that testify to the island's natural beauty and wealth. Islamic folklore maintains that Adam and Eve were offered refuge on the island as solace for their expulsion from the Garden of Eden. Asian poets, noting the geographical location of the island and lauding its beauty, called it the "pearl upon the brow of India." A troubled nation in the 1980s, torn apart by communal violence, Sri Lanka has more recently been called India's "fallen tear." Sri Lanka claims a democratic tradition matched by few other developing countries, and since its independence in 1948, successive governments have been freely elected. Sri Lanka's citizens enjoy a long life expectancy, advanced health standards, and one of the highest literacy rates in the world despite the fact that the country has one of the lowest per capita incomes. In the years since independence, Sri Lanka has experienced severe communal clashes between its Buddhist Sinhalese majority-- approximately 74 percent of the population--and the country's largest minority group, the Sri Lankan Tamils, who are Hindus and comprise nearly 13 percent of the population. The communal violence that attracted the harsh scrutiny of the international media in the late 1980s can best be understood in the context of the island's complex historical development--its ancient and intricate relationship to India's civilization and its more than four centuries under colonial rule by European powers. The Sinhalese claim to have been the earliest colonizers of Sri Lanka, first settling in the dry north-central regions as early as 500 B.C. Between the third century B.C. and the twelfth century A.D., they developed a great civilization centered around the cities of Anuradhapura and later Polonnaruwa, which was noted for its genius in hydraulic engineering--the construction of water tanks (reservoirs) and irrigation canals, for example--and its guardianship of Buddhism. State patronage gave Buddhism a heightened political importance that enabled the religion to escape the fate it had experienced in India, where it was eventually absorbed by Hinduism. The history of Buddhism in Sri Lanka, especially its extended period of glory, is for many Sinhalese a potent symbol that links the past with the present. An enduring ideology defined by two distinct elements--sinhaladipa (unity of the island with the Sinhalese) and dhammadipa (island of Buddhism)-- designates the Sinhalese as custodians of Sri Lankan society. This theme finds recurrent expression in the historical chronicles composed by Buddish monks over the centuries, from the mythological founding of the Sinhalese "lion" race around 300 B.C. to the capitulation of the Kingdom of Kandy, the last independent Sinhalese polity in the early nineteenth century. The institutions of Buddhist-Sinhalese civilization in Sri Lanka came under attack during the colonial eras of the Portuguese, the Dutch and the British. During these centuries of colonialization, the state encouraged and supported Christianity- -first Roman Catholicism, then Protestantism. Most Sinhalese regard the entire period of European dominance as an unfortunate era, but most historians--Sri Lankan or otherwise--concede that British rule was relatively benign and progressive compared to that of the Dutch and Portuguese. Influenced by the ascendant philosophy of liberal reformism, the British were determined to anglicize the island, and in 1802, Sri Lanka (then called Ceylon) became Britain's first crown colony. The British gradually permitted native participation in the governmental process; and under the Donoughmore Constitution of 1931 and then the Soulbury Constitution of 1946, the franchise was dramatically extended, preparing the island for independence two years later.