The Martyr act of St. Thecla is originally known as the Apocryphal Acts of Paul and Thecla (‘BHG 1710’), one of the most popular texts in the medieval literary Christian tradition. This text dates back to the 2nd century of our era, which makes it one of the first literary texts written in the hagiographical discourse and causes St. Thecla to be the first female saint and martyr in the Christian tradition. The Greek original is most probably translated into Old Church Slavonic in the beginnings of Slavonic literacy, meaning: towards the end of the 9th century. It enters the Slavonic tradition as the Martyr act of St. Thecla, corresponding with ‘BHBS 1’ of Ivanova’s Bibliotheca Hagiographica Balcano-Slavica (2008: 221–223). An incomplete fragment of the translation into Glagolitic (Glag. Fragm. °4) and linguistic analyses of manuscripts included in this corpus (especially Pog. 63) seem to confirm this hypothesis. However, what the translation actually looked like, has not been retraced so far. For my PhD dissertation, I am preparing the first text critical edition of this text in its medieval Slavonic translation. The primary corpus counts at least 53 manuscripts in total, spread over six monasteries and 15 different libraries, of which only seven have been edited (most of them are diplomatic or fac simile editions). At the moment, I am still gathering a quarter of the entire manuscript tradition. As far as the textual data tells us, the text has probably been translated a few times (two or three?) in different time periods and cultural contexts, which makes the reconstruction of the translation slightly more complicated. The Metaphrastic rewriting has only been translated once in the 14th century and has not been copied afterwards. This revision of the text will not be discussed in my current paper, since this translation stands on its own. What may be interesting, is the inclusion or omission of the Miracle tales of St. Thecla in the collections, which contain her Martyr act. This selection could show more light on the refinement of the textual history of the Martyr act of St. Thecla itself. In this paper, I will present my first analyses and a first rough presentation of the textual history.