Gordium was the capital city of ancient Phrygia. It was located at the site of modern Yassıhüyük, about 70–80 km southwest of Ankara (capital of Turkey), in the immediate vicinity of Polatlı district. Gordium lies where the ancient road between Lydia and Assyria/Babylonia crossed the Sangarius river.

In the 12th century BCE, Gordium was settled by Thracians who had migrated from southeastern Europe. During the 9th and 8th centuries BCE, the city grew into the capital of a kingdom that controlled much of Asia Minor west of the river Halys. The kings of Phrygia built large tombs near Gordium called tumuli, which consist of artificial mounds constructed over burial chambers. There are about one hundred of them, covering both cremations and inhumations. In the 8th century, the lower city and the area to the north of the citadel was surrounded by a circuit wall with regularly spaced towers.

The most famous king of Phrygia was the quasi-legendary Midas. Contemporary Assyrian sources dating between c. 718 and 709 BCE call him Mit-ta-a. According to the Greek historian Herodotus, King Midas was the first foreigner to make an offering at the sanctuary of Apollo at Delphi, dedicating the throne from which he gave judgment. During his reign, according to Strabo, the nomadic Cimmerians invaded Asia Minor, and in 710/709, Midas was forced to ask for help from the Assyrian king Sargon II. In Strabo's account, King Midas committed suicide by drinking bull's blood when the Cimmerians overran the city.

There is ample evidence of widespread burning of the city mound of Gordium, in a level referred to by Young as the destruction level. Archaeologists at first interpreted the destruction level as the remains of a Cimmerian attack, c. 700 BCE. The traces were later reinterpreted as dating to c. 800 BCE, largely on the basis of dendrochronology and radiocarbon analysis, although with reference to the types of objects found in the burned level. If this reinterpretation is correct, then the otherwise-unrecorded destruction would seem to have been caused by a conflagration unrelated to a Cimmerian attack. The earlier date, though, is contested, primarily on the basis of the types and styles of objects excavated in the destruction level, the latest of which are dated to c. 700 BCE by some scholars.The newly proposed radiocarbon date seems to have a range wide enough to accommodate both proposed archaeological dates, and the matter continues to be debated.

Tumulus MM (for "Midas Mound"), the Great Tumulus, is the largest burial mound at Gordium, standing over 50 meters high today, with a diameter of about 300 meters. The tumulus was excavated in 1957 by Young's team, revealing the remains of the royal occupant, resting on purple and golden textiles in an open log coffin, surrounded by a vast array of magnificent objects. The burial goods included pottery and bronze vessels containing organic residues, bronze fibulae (ancient safety pins), leather belts with bronze attachments, and an extraordinary collection of carved and inlaid wooden furniture, exceptional for its state of preservation. The Tumulus MM funeral ceremony has been reconstructed, and scientists have determined that the guests at the banquet ate lamb or goat stew and drank a mixed fermented beverage. The burial is now dated to the second half of the 8th century BCE, and while it is possible that this is the tomb of King Midas himself, it is now generally assumed to be that of his father Gordias.

According to ancient tradition, in 333 BCE Alexander the Great cut (or otherwise unfastened) the Gordian Knot: this intricate knot joined the yoke to the pole of a Phrygian wagon that stood on the acropolis of the city. The wagon was associated with Midas or Gordias (or both), and was connected with the dynasty's rise to power. A local prophecy had decreed that whoever could loose the knot was destined to become the ruler of Asia.