The research hereby presented would not be possible without the generous funding of the project "Relation between historiographical Theory and Praxis in Diodorus Siculus’ “Library of History”" by the National Science Centre, Poland (2019/32/C/HS3/00114)

Ἐπικράτεια and ἐπαρχία are two terms used by the ancient sources to describe the Carthaginian presence in Western Sicily. Due to a lack of information about the character and details of this presence, it is crucial to precisely understand the terminology employed by our sources and all its nuances. The article challenges the widely accepted opinion that the nouns ἐπικράτεια and ἐπαρχία can be treated as synonyms. To verify whether this assumption is correct or not, a careful analysis of how the ancient authors (Polybius, Diodorus Siculus and Plutarch) used both nouns, as well as other related forms, is conducted. To make up for the limited number of occurrences of ἐπικράτεια in the analysed corpus, the relevant part of the examination also includes the use of this noun in Strabo’s Geography. The analysis allows us to highlight a significant change in the meaning of the two terms between the 2nd century (Polybius) and the mid-1st century BC (Diodorus). This change reflects a development in the Greek political and administrative vocabulary, which was adjusting to a new reality of the Mediterranean world being organised into Roman provinces. The conducted analysis also allows us to better understand the complexity of the Carthaginian position in Western Sicily.