Before any type of unified political entity named Israel existed, the Jewish groups whose descendants would later form Israel identified themselves by their particular tribe. If asked their nationality or country of origin, they would likely identify themselves as Danites (from the tribe of Dan; Ex. 31:6) or Ephraimites (from the tribe of Ephraim; Judg. 12:5), etc. The main way to differentiate these tribes from other tribes in Canaan was their common worship of the deity YHWH, but in terms of language or other cultural characteristics, it would have been difficult to tell a Canaanite from an Israelite.

Eventually, these separate tribes united together as a type of confederation, allies who made a treaty (covenant) to provide military aid for one another when threatened by an enemy state. It was only under the charismatic leadership of David that the 12 tribes united into a single political entity. Scholars refer to the period encompassing the reign of David and his son Solomon as the United Monarchy. This period, spanning only two generations, was the only time when all of the tribes were politically united, and after a contentious schism that resulted because the northern tribes felt exploited by the Judean kings, the northern tribes seceded from the "United Kingdom" and reverted back to the ancient northern versus southern division of the tribes. The main difference this time was that the southern kingdom now incorporated the tribe of Benjamin, located at the border between these two new nations, within its political borders. The tribe of Simeon (south of Judah) had already ceased to maintain a separate existence (see below). The new northern kingdom adopted the name Israel, while the southern kingdom took their regional name of Judah.

The newly separated kingdoms engaged in several border disputes and skirmishes to delineate where along the northern outskirts of the territory of Benjamin the border would stand, but for the most part they remained on fairly good terms politically and even formed royal marriage alliances occasionally. Nevertheless, from that point on, the two kingdoms went their separate ways and developed separate political, economic, and religious systems.

From an outside perspective, the Kingdom of Judah was not particularly important in the Levant during the Iron Age Levant. It was a small kingdom, not even the most powerful small state in Canaan, and its survival depended on the whim of the great regional powers, most notably Egypt, Assyria, and its ultimate destroyers, the Babylonians. However, in the collective imagination of Western Civilization, it looms large because, to a great extent, the Hebrew Bible as people know it today is a chronicle of Judah and its history. That in itself is a cause of controversy, as scholars try to determine the accuracy of the ancient text, and modern politics in the region continue to be based on old ties to the land. The kingdom certainly existed, but much of the Hebrew Bible was written by writers who supported Judah, and thus it is suspected that the writers frequently overexaggerated the power and importance of the kingdom.