De Thematibus

De Administrando Imperio ("On the Governance of the Empire") is the Latin title of a Greek work written by the 10th-century Eastern Roman Emperor Constantine VII. The Greek title of the work is Πρὸς τὸν ἴδιον υἱὸν Ρωμανόν ("To [my] own son Romanos"). It is a domestic and foreign policy manual for the use of Constantine's son and successor, the Emperor Romanos II.

Constantine was a scholar-emperor, who sought to foster learning and education in the Eastern Roman Empire. He produced many other works, including De Ceremoniis, a treatise on the etiquette and procedures of the imperial court, and a biography of his grandfather, Basil I. De Administrando Imperio was written between 948 and 952. It contains advice on running the ethnically-mixed 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" (Περί Διοικήσεως τοῦ Κράτους βιβλίον καί τῶν διαφόρων Έθνῶν), concerning the histories and characters of the nations neighbouring the Empire, including the Turks, Pechenegs, Kievan Rus', South Slavs, Arabs, Lombards, Armenians, and Georgians; and the "On the Themes of East and West" (Περί θεμάτων Άνατολῆς καί 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.

The book content, according to its preface, is divided into four sections:

As to the historical and geographic information, which is often confusing and filled with legends, this information is in essence reliable.

The historical and antiquarian treatise, which the Emperor had compiled during the 940s, is contained in the chapters 12—40. This treatise contains traditional and legendary stories of how the territories surrounding the Empire came in the past to be occupied by the people living in them in the Emperor's times (Saracens, Lombards, Venetians, Serbs, Croats, Magyars, Pechenegs). Chapters 1—8, 10—12 explain imperial policy toward the Pechenegs and Turks. Chapter 13 is a general directive on foreign policy coming from the Emperor. Chapters 43—46 are about contemporary policy in the north-east (Armenia and Georgia). The guides to the incorporation and taxation of new imperial provinces, and to some parts of civil and naval administration, are in chapters 49—52. These later chapters (and chapter 53) were designed to give practical instructions to the emperor Romanus II, and are probably added during the year 951–52, in order to mark Romanus' fourteenth birthday (952).

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