Since Maurice Holleaux, the concept of “protectorate” (1921, p. 97) has been used to refer to the border space built in Illyria by Romans after their victory during the First Illyrian War (229-228 BC). However, as M. Holleaux also noticed, the Roman presence was unclear or rather non-existent after the withdrawal of the troops, right after the war. Therefore, more recently, some historians as Karl-Ernst Petzold (1971), Marjeta Šašel Kos (2004) or Danijel Dzino (2010) questioned this denomination and the reality of this so-called “protectorate” but no other lexical proposition was made before the one suggested by Arthur Eckstein. He proposed to call it an “informal sphere of influence” (2013, p. 81), considering that, even if Rome conquered all the Italian peninsula at this time, its influence in the Mediterranean area just began to emerge and it was not yet the empire it will be one century after. Thus, this study aims to rethink this border space, through an historical and historiographical lens, at a time when the Roman empire was still setting up and slowly spreading through the East. It shows that the word “protectorate” is inappropriate. Rome was mostly creating at that time a network of relationships throughout the Mediterranean area, using support points it encountered during its wars, but not directly or indirectly controlling them before the Second Illyrian War (220-219). The way Polybius wrote his history – in an imperialist way –, and the way modern scholars – following Maurice Holleaux and Polybius’ version upon the ones of Appian, Cassius Dio and Zonaras – explained why the word “protectorate” was used for so long.