This sociohistorical study probes an archaeological artefact called the Laguna Copperplate Inscription (LCI) to suggest that translingualism, a sociolinguistic orientation that foregrounds the fluidity of language boundaries, was practised by precolonial Filipinos. It then analyses how translingual practices were potentially devalued by linguistic ideologies of hierarchisation that predominantly informed the translation tasks of Spanish missionaries in the Philippines. The study ends by discussing prevailing misconceptions or myths about translingualism, drawing on findings about the LCI and other related studies.