This paper presents new proposals for the reconstruction of Proto-Basque accentuation, as well as the development and chronology of the main accentual systems of the modern dialects, grounded in phonetic, historical and typological evidence. It is the first attempt to reconstruct Basque accentuation from a pre-Roman stage to the dialectalization that followed Common Basque. We suggest that Old Proto-Basque had prosodic prominence in the root, i.e., [(C)V.'CVC]. This system evolved into phrase-level prominence in Modern Proto-Basque, giving rise to unaccentedness in non-phrase final positions, with marked stress only introduced later, through Latin loanwords (2nd–3rd century CE). This would become the common system, which still persists in the west. Not long after the dialectification, word-level systems developed in non-western areas, first as peninitial and then as penultimate stress (in eastern dialects). Finally, we propose that the Goizueta prosodic system can be derived from the Central system, which is an alternative view to Hualde (in press) .