"Old and New Territorial Dependencies : New Data about the Ager per extremitatem mensura comprehensus in the Ars Gromatica Gisemundi". The recent edition of the Ars Gromatica siue Geometria Gisemundi, which is based on two manuscripts that date from the ninth century (mostly ACA Ripoll 106), has offered new data about the literature of the Roman land surveyors. The work includes a description of the division of Spain’ s provinces in late Roman times (Discriptio Hispaniae), especially focused on the Carthaginensis region. The author based his text on several unpublished ancient sources dating from the early empire to the byzantine period. The text mentions some land surveying activities and describes some specific works in order to delimitate territories that allow us to propose the existence of a type of provincial land surveying documentation that has remained unknown until now. In addition, the document provides new information about the Byzantine presence in Spania and the possible boundaries of their occupation.