Based on the study of the encounter between the Portuguese and the Swahili in the sixteenth century, and on the analysis of the Kilwa Chronicle that resulted from it, this chapter questions the notion of ‘textual contact’. Rediscovering the way in which a text presenting the five hundred years genealogy of the kings of Kilwa could have been printed in Portuguese in Joao de Barros’s Decades in Lisbon, in 1552, is not a simple matter. While the why of the chronicle, for which there are several political reasons arising from Kilwa’s occupation in 1505, is obvious, the how of the chronicle is much less so. Through a systematic study of the two written versions of the text at our disposal, the Crónica and the Kitāb, we will show that the existence of an original manuscript which, as is generally presumed, would have been found by the Portuguese on their arrival and would have travelled up to the mouth of the Tagus, raises strong doubts. These doubts could be answered more convincingly through an alternative hypothesis, according to which the chronicle was ‘co-written’ in the sixteenth century, as a result of the encounter. In addition to the study of the conditions under which the Kilwa Chronicle was circulated in the sixteenth century, this article would like to illustrate the fact that it is impossible to express a view on the circulation of genres - and in this case of historiographic genres transiting between the Muslim world and Europe on the eve of its maritime expansion - independently of the circulation of texts embodying these genres.