Prolific Thai scholars Chris Baker and Pasuk Phongpaichit have posted a detailed Wikipedia entry about the classic Thai poem Khun Chang Khun Phaen. Here is an extract from their fascinating discussion:
Sepha Khun Chang Khun Phaen (Thai: р╣Ар╕кр╕ар╕▓р╕Вр╕╕р╕Щр╕Кр╣Йр╕▓р╕Зр╕Вр╕╕р╕Щр╣Бр╕Ьр╕Щ) is a long Thai poem which originated from a folktale. The story is a classic love triangle, ending in high tragedy. Khun Phaen (dashing but poor) and Khun Chang (rich but ugly) compete for the lovely Wanthong from childhood for over fifty years. Their contest involves two wars, several abductions, a suspected revolt, an idyllic sojourn in the forest, two court cases, trial by ordeal, jail, and treachery. Ultimately the king condemns Wanthong to death for failing to choose between the two men. The poem was written down in the early nineteenth century, and a standard printed edition first published in 1917–1918. Like many works with origins in popular entertainment, it is fast-moving and stuffed full with heroism, romance, sex, violence, rude-mechanical comedy, magic, horror, and passages of lyrical beauty. In Thailand, the story is universally known. Children learn passages at school, and the poem is a source of songs, popular sayings, and everyday metaphors. The poem is also controversial because of its male bias and violence.