Ancient Galatia is located in the central regions of modern-day Turkey, a poor land traditionally inhabited by the Phyrgians. Later this land was controlled and inhabited by Celtic tribes some time in the 270's BCE Celtic tribes in Thrace and elsewhere were invited by Nicomedes I of Bithynia to come over into Anatolia to serve as warriors and mercenaries. The term 'Galatae' was used by the Greeks to denote these Celtic tribes. Once the Galatian tribes crossed over in Anatolia, they were soon the preeminent power in the region. Raids upon nearby regions were soon commonplace. Livy writes,
To the Trocmi the coast of the Hellespont as assigned (as raiding land); the Toistoboii received by the lot Aeolis and Ionia; the Tectosages the interior parts of Asia. And they enacted tribute from all of Asia on this side of the Halys. And so great was the terror of their name, their numbers being so enlarged by great natural increase, that in the end even the kings of Syria did not refuse to pay them tribute.
All this came to an end during the 'elephant battle' against the Seleucids. The Galatians were defeated and settled down in central Asia Minor where they would continue to periodically launch raids and campaigns into he surrounding lands. The three main tribes of Galatia were the Trocmi, Tolistoboii, and the Tectosages. The Trocmi had as their capitol the town of Tavium, but also Mithridatum, Eccobriga, and Danala. The Tectosages ruled from Ankyra. They also had a settlement known as Pitobriga and they renamed the town of Gordium to Vindia, a place where they had a large market of trading goods. The Tolistoboii were centered around Blucium, later a fortress of King Deiotarus, and also Peium, an oppida where Deiotarus kept his massive treasury. Pessinus would later become the capitol of the Tolistoboii by 25 BCE during Roman annexation. The Teutobodiaci were a clan or sept within the Tectosages and the tribes of the Voturi, Ambituti, and Tosiopes were clans of the Tolistoboii.
Though little is known of the Galatians through discoveries in archaeology, the government of Galatia is known. Each tribe was split into four clans, each ruled by a tetrarch (from the Greek word tetra- meaning 'four' and arkos meaning 'chief'). These rulers were in turn supported by a chief judge, a leading general, and two deputy generals. This system held for a long time in Galatia, yet later the tetrarchs seem to have became petty kings. 300 senators held a national assembly that is thought to have been held at Drunemeton ('sacred oak sanctuary'). Despite all this the Galatians often fought among themselves and established no unified kingdom, although Ortagion, by forging alliances in the region, certainly came close to doing so. There is no mention of major problems living among the local Phyrgians nor mention of uprisings while the Galatians were away on campaign. in fact classical writers allude to their intermarrying with them.
The Galatians also adopted many aspects of Greek culture. These Celts were later known as Gallogracians, those who had Phyrgian, Greek, or other local influences in their blood and or lifestyle. Livy, quoting Manlius Vulso who defeated the Galatians in two battles in 189 BCE mentioned "that some of these Gauls (Galatians) are a mixed race, truly described by their name Gallogracians." This evidence is further backed up by the inscriptions at Delphi mentioning that among the Galatians were freed slaves of areas that they had swept through. Despite this, the Galatians were known to deal in slaves.