The Hexarchy (六邦之治, rjuk-prong-tje-lrjegh) was a period in Themiclesian history from the 3rd c. BCE to 256 CE, defined by the rule of and intermittent warfare between six states in the heartland of modern-day Themiclesia. It follows the earlier Hecatihecosiarchy (百二十邦之治) and ends with unification under the Tsjinh state in 265. This era saw the earliest centralization of political power in Themiclesia, and, borrowing extensively from Menghe, many later institutions were first introduced in this period; it is often thought of as an experimental and formative period of Themiclesian politics. The earliest received histories of Themiclesia date to this period.
From the time Themiclesia was settled by those of Meng descent, small polities are assumed to have existed, which may mainly have revolved around defence against the native societies that are now well-evidenced in archaeology. Historical documentation on these early polities are severely lacking, as official histories were only kept from around the start of the Common Era. By the late 4th or early 3rd c. BCE, the polities have consolidated into regional alliances, each dominating a particular region; these alliances may, like the polities composing of them, also possess a military character. Within each alliance, the government of each policy remained firmly in the hands of the polity's oligarchs, whether they be elders or hereditary chiefs; however, it seems some form of hereditary rulership emerged in each alliance around the beginning of the Hexarchy, assuming the title of goh (后), usually translated as "ruler" or "lord". Some scholars interpret the relationship between the goh and polity leaders as feudal, but this was not applicable in every state.
At the beginning of the Hexarchy, Meng settlements were far outnumbered by native societies. Estimates for the relative population range from 1:5 to 1:50, and the total population of Mengs in Themiclesia in the 3rd c. BCE was certainly not higher than 500,000, and they were quite diffusely distributed, since they originated as ore pursuers and animal herders.