The Theme of Seleucia was a Byzantine

Byzantine Empire

The Byzantine Empire was the Eastern Roman Empire during the periods of Late Antiquity and the Middle Ages, centred on the capital of Constantinople. Known simply as the Roman Empire or Romania to its inhabitants and neighbours, the Empire was the direct continuation of the Ancient Roman State...

 theme (a military-civilian province) in the southern coast of Asia Minor

Asia Minor

Asia Minor is a geographical location at the westernmost protrusion of Asia, also called Anatolia, and corresponds to the western two thirds of the Asian part of Turkey...

 (modern Turkey

Turkey

Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

), headquartered at Seleucia (modern Silifke

Silifke

-Antiquity:Located a few miles from the mouth of the Calycadnus River, Seleucia was founded by Seleucus I Nicator in the early 3rd century BCE, one of several cities he named after himself. It is probable that there were already towns called Olbia and Hyria and that Seleucus I merely united them...

).

History

In Late Antiquity

Late Antiquity

Late Antiquity is a periodization used by historians to describe the time of transition from Classical Antiquity to the Middle Ages, in both mainland Europe and the Mediterranean world. Precise boundaries for the period are a matter of debate, but noted historian of the period Peter Brown proposed...

, the port of Seleucia was the chief city of the Roman province

Roman province

In Ancient Rome, a province was the basic, and, until the Tetrarchy , largest territorial and administrative unit of the empire's territorial possessions outside of Italy...

 of Isauria

Isauria

Isauria , in ancient geography, is a rugged isolated district in the interior of South Asia Minor, of very different extent at different periods, but generally covering what is now the district of Bozkır and its surroundings in the Konya province of Turkey, or the core of the Taurus Mountains. In...

 and seat of the comes

Comes

Comes , plural comites , is the Latin word for companion, either individually or as a member of a collective known as comitatus, especially the suite of a magnate, in some cases large and/or formal enough to have a specific name, such as a cohors amicorum. The word comes derives from com- "with" +...

 Isauriae. In the 8th century, it is attested as a subordinate command, first under a tourmarches and then under a droungarios, of the naval theme of the Cibyrrhaeots. In the early 9th century, however, it appears as a small kleisoura

Kleisoura (Byzantine district)

In the Byzantine Empire, a kleisoura was a term traditionally applied to a fortified mountain pass and the military district protecting it. By the late 7th century, it came to be applied to more extensive frontier districts, distinct from the larger themata, chiefly along the Empire's eastern...

(a fortified frontier command) sandwiched between the larger Byzantine themes of the Cibyrrhaeots, the Anatolics, and Cappadocia

Cappadocia (theme)

The Theme of Cappadocia was a Byzantine theme encompassing the southern portion of the namesake region from the early 9th to the late 11th centuries.-Location:...

 and the sea, and bordering on the Abbasid Caliphate's domains in Cilicia

Cilicia

In antiquity, Cilicia was the south coastal region of Asia Minor, south of the central Anatolian plateau. It existed as a political entity from Hittite times into the Byzantine empire...

 along the river Lamos. According to the Arab geographers Qudamah ibn Ja'far and Ibn Khordadbeh

Ibn Khordadbeh

Abu'l Qasim Ubaid'Allah ibn Khordadbeh , author of the earliest surviving Arabic book of administrative geography, was a Persian geographer and bureaucrat of the 9th century...

, in the 9th century the kleisoura comprised Seleucia as capital and ten other fortresses, with 5,000 men, out of which 500 were cavalry.

The kleisoura was raised to the status of a full theme sometime in the reign of Romanos I Lekapenos (r. 920–944), most likely circa 927–934. According to the De Thematibus of Emperor Constantine VII

Constantine VII

Constantine VII Porphyrogennetos or Porphyrogenitus, "the Purple-born" was the fourth Emperor of the Macedonian dynasty of the Byzantine Empire, reigning from 913 to 959...

 (r. 913–959), the theme was divided in two commands, one for the hinterland and a coastal/maritime one.

The region fell into the hands of the Seljuk Turks after the Battle of Manzikert

Battle of Manzikert

The Battle of Manzikert , was fought between the Byzantine Empire and Seljuq Turks led by Alp Arslan on August 26, 1071 near Manzikert...

 in 1071. At the time, the mountainous interior of the region was predominantly inhabited by Armenians

Armenians

Armenian people or Armenians are a nation and ethnic group native to the Armenian Highland.The largest concentration is in Armenia having a nearly-homogeneous population with 97.9% or 3,145,354 being ethnic Armenian....

 who had settled there over the previous century. The Byzantines recovered the area and refortified Seleucia and Corycus

Corycus

Corycus was an ancient city in Cilicia Trachaea, Anatolia, located at the mouth of the river called Şeytan deresi; the site is now occupied by the town of Kızkalesi , Mersin Province, Turkey.-The city:...

 in 1099/1100, after which it became anew the seat of a Byzantine military governor (doux

Dux

Dux is Latin for leader and later for Duke and its variant forms ....

). It remained a Byzantine province until soon after 1180, when it was conquered by the Armenian Kingdom of Cilicia

Armenian Kingdom of Cilicia

The Armenian Kingdom of Cilicia , also known as the Cilician Armenia, Kingdom of Cilician Armenia or New Armenia, was an independent principality formed during the High Middle Ages by Armenian refugees fleeing the Seljuk invasion of Armenia...

.