Mark Wiley makes the distinction between "ancient." "classical" and "modern" Filipino martial arts in Filipino Martial Culture.
According to his classificatory system, the "ancient" Filipino martial arts "were practiced prior to the arrival of the Spanish in 1521. Generally speaking, the "ancient" arts (often referred to as kali), are structured around the use of Indonesian and Malaysian swords (i.e., kris, barong, kampilan), the use of indigenous projectile weapons (i.e., sumpit, pana), the use of flexible weapons (i.e., kadena, panyo, with footwork patterned around geometric shapes. Preserved in the unconquered Muslim areas of the southern Philippines, these arts did not undergo the same evolutionary process as did eskrima and arnis. Therefore, the "ancient" art of kali could not have possibly maintained eskrima or arnis in its curricular phases - Spain, the United States, and Japan had not, as of the height of the this art's popularity in the archipelagio (prehistory to A.D. 1521), dominated the Philippines." (p. 313)
Note: here Wiley is intentionally using the word "kali" to refer to the Filipino martial art of weaponry prior to 1521 only in a global sense and not to a specific martial art called "kali," which he elsewhere argues did not exist per se.
As for how far back "kali" goes prior to 1521, I would argue that it goes as far back as human beings acquired and used weapons to hunt and to defend themselves.
What follows is a paraphrase of Wiley with respect to the above:
Archeological findings in 1962 that are considered evidence of remains of Homo sapien were carbon-dated to approximately 22,000 B.C.
Wiley accepts Jocano's assertion that geological records suggest that the Philippines were once part of the Asian mainland, and that, rather than successive "waves" of Malay and Indonesian peoples transplanting their cultures upon the indigenous Filipinos in whole, "Indonesians, Malays, and Chinese island-hopped across it on their way to trading posts in other countries." (p. 34) (I take it that the oceans must have risen after the ice-age to account for the Philippines becomming islands.)
Based on this record, it is probable that "ancient" Filipino martial arts, in some form or another, were practiced prior to their influence by Indonesian, Malay, and Chinese cultures. In some cases (for example, interior or mountain tribes), they may not have received any influence at all. Several Pacific tribes were, after all "discovered" up until the 1930's with little or no prior contact with outside cultures (and perhaps someone with more knowledge of Filipino history than I possess can tell me if this case holds for the Philippines.)
After the influx of sailing vessels from Indonesia, Malaysia, and China from 500 B.C. to 900 A.D., Jocono further notes that about 1000 A.D., "Filipino contacts with the outside world became intensified. The major impetus being a relatively efficient maritime transportation." (p. 34).
By 1293, however, the influence of successive Indonesian empires (Srivijayan, Madjapahit) that regulated trade between China and India led to changes in prehistoric Philippine communtity life, "including specialization of labor, and a stratified social organization (political, economic, religious, etc.). There developed a need to protect the land that a given group had claimed as their own through farming and taming of animalsl I]As a result, the development of crude combatives implementing the empty hands and various hunting tools began to surface.[/I] (p. 34, emphasis mine)
In addition, Philippine-Chinese contacts intensified during the Tang period and reached their height around the 14th to 15th centuries. Wiley states that Chinese fighting arts were taught to members of the royal Filipino families as a good-faith gesture to strengthen trade agreements.
Wiley states that, "(a)though we can neither prove nor disprove the actual progression of the peopling of the Philippines, we do know that the archipelago had extensive prehistoric contact with Indonesia, Malaysia, and China. It follows, then, that there is not a single-source from which Filipino martial arts developed, but at least three. Therefore, we must view the "ancient" Filipino martial arts as artifacts of a time and place. While they may have had common origins, differences evolved over time as a result of changing environmental conditions and the cultural experiences of the inhabitants in three island regions, Luzon, the Visayas, and Mindanao." (p. 35)
Anyhow that's my paraphase of Wiley, for better or worse. In his bibliography, he cites Jocomo's Philippine Prehistory, as well as numerous other texts. If anyone can recommend some other references, please let me know.
Best,
Steve Lamade