The theme of Seleucia (Greek θέμα Σελευκείας, theme Seleukeias ) was a Byzantine theme on the southeast coast of Asia Minor ( now Turkey ), whose capital was Seleucia (now Silifke ).
In late antiquity, the port of Seleucia was Calycadnus the principal port of the province and the seat of Isauria Comes Isauriae. In the 8th century a tour March and later a Droungarios the theme of Kibyrrhaioten was here first stationed. In the early 9th century Seleucia ( a boundary command ), which was of the great Byzantine themes of Kibyrrhaioten, the topic of Anatolia, the theme of Cappadocia and the Mediterranean and bordered directly to the Abbasidenkalifat in Cilicia appears as Kleisoura. The Arab geographer ibn Ja'far and Ibn Qudamah Chordadhbeh included the kleisoura of Seleucia in the 9th century noc ten other fortresses and had 5000 soldiers, of whom 500 were mounted.
The kleisoura was raised during the reign of Romanus I (reigned 920-944 ) to a full-fledged theme, probably between 927-934. The work De Thematibus of the Emperor Constantine VII (reigned 913-959 ), according to the subject was split into two districts, one. Along the coast and one in the back country
After the Battle of Manzikert, the region fell to the Seljuks in the hands. At this time, the interior of the topic was mainly populated by Armenians who had been settled there in the last century. In the year 1099/1100 the Byzantines retook the region and fortified Seleucia and Korykos strong. Seleucia was the seat of a ( Doux ). It remained until shortly after 1180 a Byzantine province, when it was conquered by the Kingdom of Lesser Armenia.