The analysis of the legal sources of the second and third centuries AD,aims to highlight the fact thatthe inclusion of the sea among the res communes omnium, and the same this category developed by Marcian are not so much the mature fruit of the discussions developed among the imperial jurists but, on the contrary, an attempt to build a special category within the res publicae, open to anyone regardless of Roman citizenship, which, however, when it was created by Marcian, would need further reflection. However, such an in-depth study was not possible due to the lack of scientific activity of the jurists after Gordian lll. A close analysis of the scene of Plautus' Rudens is also carried out, in order to attempt a correct framing of the discussion on the historical process that involved the definition of the sea as res communis omnium.
