Queen Hijau (The Green Queen) of Pattani faces overthrow by the rebel Prince Rawai, who is allied with pirate captain Black Raven. The pirates attempt to capture some giant cannon invented by Dutchman Janis Bree and Chinese inventor Lim Kium, but the Dutch ship carrying the cannon blows up and the cannons sink into the sea.
Meanwhile, an orphan sea gypsy boy named Pari is raised in a fishing village, which is constantly under attack by Black Raven's raiding parties. The boy, gifted in the magical art of Du Lum, is taken by his uncle Anjar to learn more of the magical ways of the ocean from White Ray, but the sage refuses to teach the boy. Nonetheless, Pari is soon communicating with the marine life. He grows into manhood and becomes a fighter against Black Raven's pirates.
Black Raven, also a practitioner in the Du Lum ocean magical arts, has been trying to raise the cannons from the depths of the sea.
Queen Hijau wants her own large cannons and seeks the inventor Lim Kium, who has been living in the sea gypsy fishing village. She sends away her sisters, Princess Ungu (The Purple Princess) and Princess Biru (The Blue Princess). They will be under the protection of the queen's loyal commander, the fierce silat exponent Lord Jarang.
At the fishing village, Lord Jarang comes under attack. Pari aids Jarang in fighting off the pirates, and Jarang makes his escape. In the confusion, Princess Ungu is believed to have been killed, but she has actually been rescued by Pari and taken to White Ray's remote island.
There, a romance develops between Ungu and Pari, but neither are able to commit. Ungu is due to marry the Prince ofPahang, an important ally of Langkasuka. And Pari is still tortured by the death of his childhood sweetheart at the hands of Black Raven's men.
In a cave on the island, Pari encounters Black Ray, an evil, unstable alter ego of White Ray, and Pari begins to learn more about Du Lum and the conflict between the black and white sides of the practice.
Eventually, all the forces - the rebel prince, the pirates, the ocean sorcerers, the queen and the princesses - will battle for the big cannon.
Queens of Langkasuka, which went into production in 2005, was at first called Queens of Pattani, but the name was changed to avoid political connections to the South Thailand insurgency and Pattani separatism, and to tie the story in with the legend of Langkasuka.
The film premiered at the 2008 Cannes Film Market to mixed reviews. Derek Elley of Variety said the film lacked focus and at 133 minutes was too long. Maggie Lee ofThe Hollywood Reporter was more upbeat, praising the sumptuous costume design and action sequences, but also said the film was too long.
Based on the reception from the industry press, studio Sahamongkol Film International pushed for a shorter version of the film. The film's August 2008 release in Thai cinemas was postponed until October, with the director citing Thailand's unstable political atmosphere.
A boost of confidence was given though, when the film was scheduled for the Venice Film Festival, where it would play in a special out-of-competition midnight screening.Queens of Langkasuka was also the "gala opening" film for the 2008 Bangkok International Film Festival.