Datu Kalantiaw (Rajah Bendahara Kalantiaw) (sometimes spelled Kalantiao) is a mythical Filipino character was said to have created the first legal code in the Philippines, known as the Code of Kalantiaw, in 1433.
The code was contained in one of five manuscripts acquired from Jose E. Marco by the Philippine Library in 1914. The manuscript, Antiguas Leyendas is the only source of the Code. Historian William Henry Scott asserted in his PhD thesis, Critical Study of the Prehispanic Source Materials for the Study of Philippine History that there is no evidence that any Filipino ruler by the name of Kalantiaw ever existed or that the Kalantiaw penal code is any older than 1914. Scott successfully defended the thesis in 1968 before a panel of emminent Filipino historians which included Teodoro Agoncilla, Horacio de la Costa, Marcelino Foronda, Nicolas Zafra, and Gregorio Zaide. The thesis was published by University of Santo Tomas Press Press in 1968. Filipino historians agreed to remove mention of the Code from future readings regarding Philippine history.
In 1917, the historian Josue Soncuya published a Spanish translation of the code in 1917, and wrote about it in his book Historia Prehispana de Filipinas (Prehispanic History of the Philippines). Soncuya concluded that the Code had been written for Aklan because of the presence of two Aklanon rather than Hiligaynon words in the text, and the words Aklan, Panay Island were added to later versions of Soncuya's translation (viz. "Echo en al año 1433–Calantiao–3° regulo").
Other authors throughout the 20th century, and up to the present day, recognized the story. The Code of Kalantiaw is no longer a part of the standard history texts in the Philippines but the story is still believed by people in the Visayas.