[1][10] Archeological findings in Santa Ana have produced the oldest evidence of continuous habitation among the Pasig River polities, pre-dating artifacts found within the historical sites of Maynila and Tondo.

[5][9][Notes 1] Historians studying Namayan have the advantage of being able to draw both from written sources and from artifacts uncovered in controlled archeological digs.

[2] Controlled archaeological excavations conducted by the National Museum of the Philippines in the 1960s, meantime, produced artifacts from a pre-Hispanic grave site within the Santa Ana Church complex,[5][9] providing important information about maritime trade around Southeast Asia and China from 12th to 15th century AD, as well as the elaborate mortuary practices of Namayan's inhabitants.

"[2] Instead of the Sapa site, local traditions say that an area called Lamayan (Tagalog and Kapampangan for "the place where a wake was held"), on the banks of the Pasig itself.

de Huerta, who, noting that Namayan was a confederation of several barangays, identified these component communities as they were named during the mid 19th century.

[3] Huerta describes the original settlement in Santa Ana as a fishing village that had other industries including carpentry, masonry, piña (pineapple cloth) embroidery, tinapá, cigars, bricks, sugar and bread.

Under the heading "Santa Ana", he records: "In origin of the natives of this town comes from a ruler ("regulo") called Lacantagcan, and his wife named Bouan, lords ("señores") of the Namayan territories [...] The first Christian name found in the genealogical tree of this great ("gran") family is a certain Martin in this form.

"[2]Historian William Henry Scott notes that "Rajah Kalamayin" was the name of the ruler of Namayan at the point of colonial contact in the early 1570s,[1] and Huerta here records that his son was baptized "Martin" upon conversion to Roman Catholicism.

Huerta does go on, however, to mention that Lacantagcan had another male son, named Pasay, whose mother was a Bornean slave: "The said Lacantagcan, in addition to five children of his legitimate wife Bouan, had a bastard ("bastardo") with a slave of Bornean lineage ("esclava de casta bornea"), called Pasay, who was the origin of the town known by the same name, for having fixed there his residence as landowner, supported by his father.

[2] Historian Grace Odal-Devora notes that Kapampangan oral histories also mention a "Sultana Kalangitan", described as "the Lady of the Pasig" who ruled the "Kingdom of Namayan."

[10] The rulers of Namayan from the period of colonial contact (the 1570s) back to three prior generations, were documented by Franciscan Historian Fray Felix Huerta in the work Estado geográfico, topográfico, estadístico, histórico- religioso de la santa y apostólica Provincia de San Gregorio Magno ("Geographical, topographical, statistical, historical and religious state of the holy and apostolic province of St. Gregory the Great"), a record of the histories of Franciscan missions which is now a primary resource for local histories of Philippine municipalities.

Ana de Sapa was founded in 1578, Franciscan missionaries chose to build their church, and eventually another settlement, some distance away from the ancient town.