De Thematibus

Author and background

It contains advice on ruling the heterogeneous empire as well as fighting foreign enemies. The work combines two of Constantine's earlier treatises, "On the Governance of the State and the various Nations" (Περὶ Διοικήσεως τοῦ Κράτους βιβλίον καὶ τῶν διαφόρων Ἐθνῶν), concerning the histories and characters of the nations neighbouring the Empire, including the Hungarians, Pechenegs, Kievan Rus', South Slavs, Arabs, Lombards, Armenians, and Georgians; and the "On the Themes of East and West" (Περὶ θεμάτων Ἀνατολῆς καὶ Δύσεως, known in Latin as De Thematibus), concerning recent events in the imperial provinces. To this combination were added Constantine's own political instructions to his son, Romanus.