Ulpian and the public uses of imperial properties. A note on Digest 30, 39, 7-10

This piece seeks to explain why Ulpian, in a famous passage of his commentary on sabinus, refers to the Gardens of sallust and the albanum as typically non sellable imperial properties. the history of the two imperial demesnes proves key to interpreting Ulpian’s fragment: they were the only two imperial residences in the suburbium in whose vicinity military camps were established. this gives a sufficiently clear explanation as to why their use may be considered public by Ulpian and clarifies a highly disputed point among romanists, i.e. that there was no legal difference among imperial properties with regard to their alienability.