Maragtas refers to the Visayan tale where ten datus and their families from Borneo emigrated via rafts to Panay Island. These families were the ancestors of modern Visayans, and by extension, Filipinos.
How do historians know about events that occurred in the Philippines before the time of the Spaniards? How do they know the names of the people who lived then and the things they did if there are almost no authentic written documents from that era?
Much of what we know about the prehispanic era came to us through legends. These are stories that were not written but were spoken by each generation to its following generation. Many legends are usually nothing more than stories about the creation of the world, the first man and woman and such. It is easy to see that these are not meant to be regarded as fact. There are some legends that may have a been based on actual events but they are not reliable records of the past because legends can change with each telling. Often a teller's memory can be weak or mistaken or the teller may even add or remove parts of the story just to spice it up.
Although previously accepted by some historians, including the present authors, it has become obvious that the Maragtas is only the imaginary creation of Pedro A. Monteclaro, a Visayan public official and poet, in Iloilo in 1907. He based it on folk customs and legends, largely transmitted by oral tradition. M17E
It would be unfair to brand Pedro Monteclaro a hoaxer or his book a fraudulent document because he never claimed that Maragtas was anything more than a collection of legends. Any frauds involving his book were perpetrated by other later writers who misrepresented it as an authentic ancient document.