The Epistola Presbiteri Iohannis is structurally divided in two sections: in the first section, written in epistolary style, the Presbiter, introducing himself as dominus dominantium, addresses the Byzantine emperor Manuel; in the second one, the purported dominus describes his power and his domain, identified as India. The aim of the present article is to shed light on the relationship between these two sections of the Epistola, to better understand the compositional process of the whole work. The textual analysis suggests that the epistolary section was probably written without foreseeing the subsequent mirabilia:the description of the reign was progressively created and integrated in a following phase, and it changed the perspectives and the intentions of the whole text. Some remnants of this process are still visible in two textual versions, preserved in a few ancient manuscripts – i. e. the form called Kurzfassung u by Bettina Wagner (2000), the first one to draw attention to it. The primordial disjunction of these two sections may explain the ambiguities of the text, which can hardly be traced back to a single purpose and warn against overly univocal interpretations of this puzzling work.