Classical and Early Modern Spanish demonstrative forms esotro / estotro have not yet been studied in-depth. In this contribution, we defend their autonomous character with respect to sequences with a demonstrative and otro (este / ese + otro), hence arguing for the existence of an individual grammaticalization itinerary. Based on an exhaustive analysis of the data in the CORDE corpus, we place their origin in the dialects of the Western part of the Iberian Peninsula and expound on the chronology of their birth, raise and decline, illustrating how they generalized following a cluster of discourse traditions.