Laodicea, a titular see, of Asia Minor, metropolis of Phrygia Pacatiana, said to have been originally called Diospolis and Rhoas; Antiochus II colonized it between 261 and 246 B.C., and gave it the name of his wife, Laodice. The city stood on a spur of Mount Salbacus, one mile from the left bank of the Lycus, between the Asopus and Mount Cadmus; its territory lay between the Lycus and the Caprus. In 220 B.C. Achaeus was its king; then it formed part of the Kingdom of Pergamus, and suffered severely during the war with Mithridates, but recovered its prosperity under Roman rule. About the end of the first century B.C. it was one of the principal cities of Asia Minor, both as to industries and commerce, being famous for its woollen fabrics and its sandals. It had received from Rome the title of free city, and it became the center of a conventus juridicus, which comprised twenty-four cities besides itself. Its wealthy citizens embellished it with beautiful monuments. One of the chief of them, Polemon, became King of Armenian Pontus—called after him "Polemoniacus"—and of the coast round Trebizond. The city had a school of medicine and gave birth to the two sceptic philosophers, Antiochus and Theiodas. Its coins and inscriptions show evidence of the worship of Zeus, Aesculapius, Apollo, and the emperors. It is frequently mentioned by the Byzantine historians, particularly in the epoch of the Comneni, and was fortified by the Emperor Manuel. The Mongol and Turkish invasions brought on its decay, and then its complete ruin. Its magnificent remains are to be seen near the village of Denizli, formerly and more exactly called Denizli Ladik (Ladik=Laodicea), in the vilayet of Broussa; they consist principally of a stadium, three theatres, an aqueduct, sarcophagi, etc.
At the beginning of the Christian era, Laodicea was inhabited, besides its indigenous population of Hellenized Syrians, by Greeks, Romans, and an important Jewish colony. There is extant a letter from the authorities of the city to a Roman magistrate in which the former undertake to refrain from molesting the Jews in their religious observances and customs. These Jews sent regularly to Jerusalem a tribute of twenty pounds of gold. Christianity penetrated into the city from the earliest times: St. Paul mentions the Church of Laodicea as closely united with that of Colossus. It had probably been founded by the Colossian Epaphras, who shared the care of it with Nymphas, in whose house the faithful used to assemble. Paul asks the Colossians to communicate to the Church of Laodicea the letter which he sends to them, and to read publicly that which should come to them from Laodicea, that is, no doubt, a letter which he had written, or was to write, to the Laodiceans (Col., ii, 1 sq.). An apocryphal epistle purporting to be from Paul to the Laodiceans is extant in Latin and Arabic (see Apocrypha). Some of the Greek MSS. end the First Epistle to Timothy with these words: "Written at Laodicea, metropolis of Phrygia Pacatiana". The Church of Laodicea is one of the seven (see Ramsay, The Seven Churches of Asia Minor, London, 1908) to the bishops of which are addressed the letters at the beginning of the Apocalypse (Apoc., iii, 14-21). The first bishops attributed to the See of Laodicea are very uncertain: St. Archippus (Col., iv, 17); St. Nymphas (Col., iv, 15; already indicated as bishop of Laodicea by the Apostolic Constitutions, vii, 46); Diotrephes (III John, 9). Next comes St. Sagaris, martyr (c. 166). Sisinnius is mentioned in the Acts of the martyr St. Artemon, a priest of his Church. Nunechius assisted at the Council of Nicaea (325). Eugenius, known by an inscription, was probably his successor. The Arian Cecropius was transferred by Constantius to the See of Nicomedia. When Phrygia was divided into two parts, Laodicea became the metropolis of Phrygia Pacatiana: it figures under this title in all the "Notitiae episcopatuum". Some twenty incumbents are known besides those already enumerated; the last occupied the see in 1450.
There are extant, in Greek, sixty canons of a Council of Laodicea. That this assembly was actually held, we have the testimony of Theodoret ("In Coloss." ii, 18, P.L., LXXXII, 619). There has been much discussion as to the date: some have even thought that the council must have preceded that of Nicaea (325), or at least that of Constantinople (381). It seems safer to consider it as subsequent to the latter. The canons are, undoubtedly, only a resume of an older text, and indeed appear to be derived from two distinct collections. They are of great importance in the history of discipline and liturgy; Protestants have often, but quite without reason, invoked one of them in opposition to the veneration of angels.