Constantine Porphyrogenitus and the De administrando imperio

Abstract The misnamed De administrando imperio is a historically enriched guide to foreign relations. It was presented by Constantine Porphyrogenitus to his 14-year-old son Romanos in 952. It is an odd work—ramshackle, untidy, but with a coherent core. This core originated as a handbook of diplomacy commissioned by his father, Leo VI, to complement his Tactics. It was narrowly focused on actual and potential allies and clients in four arenas of active diplomacy—Italy, the Balkans, the Ukrainian steppes, and Transcaucasia. It was unfinished at Leo’s death. Constantine took it over in the 930s and 940s, updating each of its four constituent dossiers, introducing new material (glosses, additional background history, miscellaneous information only tangentially connected with diplomacy, and a handy guide to northern diplomacy), and prefacing it with advice to Romanos and a prayer for his success.