This paper offers a synchronic and diachronic analysis of the diverse forms in Old Latin (third–second century BCE) that can be connected to Proto-Indo-European (PIE) *s(w)e-: se, sibi, sum, sam, sos, sas, sis, ipse. We classify our sample according to different grammatical, semantic, and pragmatic values, such as the construction type, animacy, and topicality of their referents. Among the results, we show that se and sibi are not primarily used as reflexives and that they share remarkably similar grammatical, semantic, and pragmatic features with the rest of the studied forms. These findings lead us to support the hypothesis of a single etymological origin in the PIE *s- + vowel (*sV) root and to further claim that this root was not a reflexive or a simple anaphoric marker, but a demonstrative pronoun that ranked high in a referential hierarchy.