The Merdicas (also spelled Mardicas or Mardikas) were Catholic natives of the islands of Ternate and Tidore of the Moluccas, converted during the Portuguese occupation of the islands by Jesuit missionaries. The islands were later captured by the Spanish who vied for their control with the Dutch. In 1663, the Spanish garrison in Ternate were forced to pull out to defend Manila against an impending invasion by the Chinese pirate Koxinga (sacrificing the Moluccas to the Dutch in doing so). A number of Merdicas volunteered to help, eventually being resettled in a sandbar near the mouth of the Maragondon river (known as the Bahra de Maragondon) and Tanza, Cavite, Manila.
The invasion did not occur as Koxinga fell ill and died. The Merdicas community eventually integrated into the local population. Today, the place is called Ternate after the island of Ternate in the Moluccas, and the descendants of the Merdicas continue to use their Spanish creole (with Portuguese influence) which came to be known as Caviteño or Ternateño Chavacano.
In addition to Tagalog, the community of Merdicas continue to use a broken Spanish with Portuguese elements, which evolved into the full-fedged Philippine Spanish creole called Ternateño or Ternateño Chavacano. It is still spoken by about 20% of the population, most of whom are elderly people. The language is expected to disappear in the future. It is considered to be very close to Chabacano Caviteño and Chabacano Ermiteño.