Paristrion (Greek: Παρίστριον, lit. 'beside the Ister'), or Paradounabon/Paradounabis (Παραδούναβον / Παραδούναβις), which is preferred in official documents, was a Byzantine province covering the southern bank of the Lower Danube (Moesia Inferior) in the 11th and 12th centuries.
Although Byzantine authors use the term to describe the lands along the Danube in general, the province of Paristrion seems to have comprised mostly modern Dobruja. It is not certain exactly when the province was established: the Romanian scholar Nicolae Bănescu considered that it was established immediately after the end of the Rus'–Byzantine War of 970–971, while others, such as Vasil Zlatarski, thought it a later, mid-11th century creation. It was governed by a katepano or a doux, and was probably based at Dorostolon (modern Silistra), where a Byzantine strategia ("generalcy") is indeed attested in the 970s. In the aftermath of his victory over the Rus', Emperor John I Tzimiskes (r. 969–976) appointed general Leo Sarakenopoulos as commander over north-eastern Bulgaria, based at Pereyaslavets/Ioannopolis. Sarakenopoulos and his subordinates engaged in major fortification activities in the region of the Dobruja over the next few years, where abandoned Roman-era forts were rebuilt and re-occupied.
