ΚΩΝΣΤΑΝΤΙΝΟΥ ΒΑΣΙΛΕΩΣ ΒΙΒΛΙΟΝ ΤΑΚΤΙΚΟΝ-ΤΟΥ ΣΟΦΩΤΑΤΟΥ ΒΑΣΙΛΕΩΣ ΚΩΝΣΤΑΝΤΙΝΟΥ ΤΟΥ ΠΟΡΦΥΡΟΓΕΝΝΗΤΟΥ ΠΕΡΙ ΘΕΜΑΤΩΝ - ΚΩΝΣΤΑΝΤΙΝΟΥ ΤΟΥ ΠΟΡΦΥΡΟΓΕΝΝΗΤΟΥ ΝΕΑΡΑΙ. Constantini Porphyrogeniti Imperatoris Opera in quibus Tactica - De Thematibus-Novellae, Lugduni Batavorum (Leiden) Elzeviriana 1617 EDITIO PRINCEPS for the Tactica, second edition for the De Thematibus and the Novellae. In 8vo,18x13cm, contemporary full vellum in fine condition, old stamp of Halle gymnasium on title,58p., [4],307p., a fine copy overall. Tactica text only in the original Greek. The rest, Greek text and Latin translations. Extensive notes in Latin. Very early editions of several works of Konstantinos Porphyrogenetus, edited by the famous Meursius (van Meurs 1579-1639), the best classical scholar of his time, who dreamed to create a new Athens in Leiden. The Tactica is a byzantine military treaty of the 10th century, full with valuable information, contains early references on the Greek fire (υγρό πυρ) and on Byzantine ships (δρόμων). The Thematibus (Περί Θεμάτων) is the detailed description of the administrative structure of Byzantium in 10th century, it is a unique source for the history of geography of the Balkans and Asia Minor, as it described cities and places otherwise unknown. Precious for the medieval Greek place names in Anatolia. It provides the names of many towns and forts that were destroyed during the later Seljuk and Ottoman invasions. Constantine explicitly discusses the Hellenization of various regions. It is a key text for understanding how the Byzantines viewed their own identity, as both Romans, [Ρωμαίοι] and heirs to Greek culture Τhe book is a Complete Manual of the Byzantine State. It is one of the very few contemporary medieval detailed geographical descriptions of the Levant.