Antiquity

Located a few miles from the mouth of the Göksu River, Seleucia was founded by Seleucus I Nicator in the early 3rd century BC, one of several cities he named after himself. It is probable that there were already towns called Olbia (or Olba) and Hyria and that Seleucus I merely united them giving them his name. The city grew to include the nearby settlement of Holmi (in modern-day Taşucu) which had been established earlier as an Ionian colony but being on the coast was vulnerable to raiders and pirates.^[5] The new city up river was doubtless seen as safer against attacks from the sea so Seleucia achieved considerable commercial prosperity as a CIlician port, and was even a rival of Tarsus.^[4]

Cilicia thrived as a province of the Romans, and Seleucia became a religious center with a renowned 2nd century Temple of Jupiter. It was also the site of a noted school of philosophy and literature, the birthplace of peripatetics Athenaeus and Xenarchus.^[6] The Silifke Bridge was built by the governor L. Octavius Memor in 77 AD.

Christianity

Early Christian bishops held the Council of Seleucia on 27 September 359.^[7] Seleucia was famous for the tomb of the virgin Saint Thecla of Iconium, converted by Saint Paul, who died at Seleucia,^[8] the tomb was one of the most celebrated in the Christian world and was restored several times, among others by the Emperor Zeno in the 5th century, and today the ruins of the tomb and sanctuary are called Meriamlik.^[9] In the 5th century the imperial governor (comes Isauriae) in residence at Seleucia had two legions at his disposal, the Legio II Isaura and the Legio III Isaura. The Christian necropolis, west of town, which contains many tombs of Christian soldiers, likely dates from this period.^[10] According to the Notitia Episcopatuum of the Patriarchate of Antioch, in the 6th century, the Metropolitan of Seleucia had 24 suffragan sees.^[11]

By 732 nearly all the ecclesiastical province of Isauria wrre incorporated into the Patriarchate of Constantinople; henceforth the province figures in the Notitiae of the Patriarchate of Constantinople, under the name of Pamphylia.

In the Notitiae of Leo VI the Wise (ca. 900) Seleucia had 22 suffragan bishoprics,^[12] while in that of Constantine Porphyrogenitus (ca. 940) it had 23.^[13] In 968 when Antioch was recaptured by the Byzantines, Seleucia was allocated to the Patriarchate of Antioch.^[14] There were several metropolitans of this see, the first of whom, Agapetus, attended the Council of Nicaea in 325, Neonas was at the Council of Seleucia in 358, Symposius at the Council of Constantinople in 381, Dexianus at the Council of Ephesus in 431, Basil, a celebrated orator and writer, whose conduct was rather ambiguous at the Second Council of Ephesus and at the beginning of the Council of Chalcedon in 451, Theodore was at the Fifth Ecumenical Council in 553, and Macrobius was at the Sixth Ecumenical Council and the Council in Trullo in 692.

No longer a residential see, Seleucia in Isauria was included in the list of titular sees of the Catholic Church, which made no new appointments of a titular bishop to this eastern see since the Second Vatican Council.^[15]

Medieval period

In 705 Seleucia was temporarily captured by the Umayyads and was soon recovered by the Byzantines. In the 8th century Seleucia was ruled by a tourmarches and then under a droungarios, as part of the Cibyrrhaeot Theme.^[16] In the early 9th century, it appears as the capital of a kleisoura bordering on the domains of the Abbasid Caliphate in Cilicia. According to the Arab geographers Qudamah ibn Ja'far and Ibn Khordadbeh, in the 9th century the kleisoura comprised Seleucia as capital and ten other fortresses, with 5,000 men, out of which 500 were cavalry.^[17][18] The kleisoura was raised to the status of a full theme around 927-934 during the reign of Romanos I Lekapenos, as the Theme of Seleucia.^[19]

In the 11th century, the city was sacked by the Seljuk Turks, and was soon recaptured by the Byzantines in 1099/1100 during the reign of Alexios I Komnenos, who rebuilt the city and fortified it.^[20] On 26 February 1180 Seleucia was conquered by the Armenian Kingdom of Cilicia. On 10 June 1190 Frederick Barbarossa drowned while trying to cross the Calycadnus river, near Seleucia, during the Third Crusade.^[4]

In the 13th century Seleucia was in the possession of the Knights Hospitaller, until it fell to the Karamanids in the second half of the 13th century, and then to the Ottomans under Gedik Ahmet Pasha in 1471.^{[citation needed]}

Modern period

Until 1933, Silifke was the capital of İçel Province until the İçel and Mersin provinces were merged. The merged province took the name of İçel but its administrative centre was at Mersin. In 2002 the name of İçel was replaced with that of Mersin.^{[citation needed]}