Side, ancient Pamphylia's largest port, is situated on a small peninsula extending north-south into the sea.

Strabo and Arrianos both record that Side was settled from Kyme, city in Aeolia, a region of western Anatolia. Most probably, this colonization occurred in the seventh century B.C.. According to Arrianos, when settlers from Kyme came to Side, they could not understand the dialect. After a short while, the influence of this indigenous tongue was so great that the newcomers forgot their native Greek and started using the language of Side. Excavations have revealed several inscriptions written in this language. The inscriptions, dating from the third and second centuries B.C., remain undeciphered, but testify that the local language was still use several centuries after colonization. Another object found in Side excavations, a basalt column base from the seventh century B.C. and attributable to the Neo Hittites, provides other evidence of the site's early history. The word "side" is Anatolian in origin and means pomegranate.

Next to no information exists concerning Side under Lydian and Persian sovereignty. Nevertheless, the fact that Side minted its own coins during the fifth century B.C. while under Persian dominion, shows that it still possessed a great measure of independence.

In 333 A.D., despite its strong land and sea walls, Side surrendered to Alexander the Great without a fight. For a long period following the death of Alexander, Side came under the dominion of the Ptolemaic and Seleucid Empires, and in 190 B.C. witnessed a great naval battle. This encounter took place between the fleet of Rhodes, acting with the support of Rome and Pergamum, and the fleet of Antiochos III, the king of Syria, under the command of the famous Carthaginian Hannibal. Side took the side of Hannibal, but the Rhodian forces carried the day.

In the second century B.C. Side was able to stave off the forces of the Attaleids of Pergamum and preserve its independence, becoming a wealthy commercial, intellectual, and entertainment centre. Side's importance in the Eastern Mediterranean as an educational and cultural centre can be gauged by the fact that Antiochos VII, who ascended the throne of Syria in 138 B.C., was sent to Side in his youth to receive its education. In the first century B.C. misfortune overtook Side in the form of Cilician pirates, who seized the city and turned it into a naval base and slave market. The people of Side seem to have tolerated the pirates because of the highly profitable nature of this commerce, which, however, gave the city a bad name in the region. Stratonicus, a man famous for his retorts and witticisms, answered the question, "Who are the worst, most treacherous people?" saying, "In Pamphylia the people of Phaselis, but in the whole world the people of Side". The famous Roman general Pompey ended the reign of the pirates in 67 B.C. and Side, by erecting monuments and statues in his honour, tried to erase its bad name.

Under Roman rule, Side prospered during a second golden age, especially in the second and third centuries when it became a metropolis ,seat of the provincial governor and his administrative staff. Due to its large harbour. Side in this era enjoyed commercial relations throughout the Mediterranean particularly with Egypt. Imported goods left Side for central Anatolia by road. Side's importance as a commercial centre can be ascertained by the hundreds of shops occupying not only the main streets, but also the narrowest of side streets and alleys. At the same time it continued as an important slave trading centre. Documents from the Imperial Roman period found in Egypt report that these slaves were sent to Side mainly from Africa. It is also known that Side possessed a large commercial fleet which did not pass up opportunities to commit piracy. Maritime commerce was the origin of the wealth of many merchants. These wealthy men did not work solely to increase their fortunes, but also provided for activities benefiting the people of the city, donating large sums to organize competitions and games, as well as to beautify the city and create social and religious organizations. One inscription found above a late period gate reports that two people, whose names cannot be made out, had a deipnisterion or soup kitchen erected for the use of government employees and the council of elders. A woman named Modesta organized gladiatorial events; Tuesianos, another inhabitant of Side, organized a feast to celebrate the return of the seamen to Side; and a husband and wife pair of philanthropists provided for the repairs of Side'' water system out of their own pockets. A great proportion of the buildings and monuments still standing at Side date to this magnificent epoch.