Last year, archaeologists discovered lumps of clay (known as bullae) made for sealing documents in Khirbet Summeily in the Negev. Their presence suggests a higher degree of political organization in 10th-century BCE Israel than was previously thought, thus lending greater credibility to the biblical books of Samuel and I Kings. James Hardin, Christopher Rollston, and Jeffrey Blakely explain what this discovery implies (free registration required):
A seal of the parties to an agreement would be impressed into the soft clay leaving an impression. A document “sealed” in this fashion would not be opened (that is, the seal would not be broken) unless there was some legal reason to do so, for example, in some sort of a court case where the contents of the document were at issue. . . . The precise material that the Summeily bullae “sealed” is still in the process of analysis. . . . But the practice of sealing is an elite or official activity.
We believe that the remains discovered at Summeily demonstrate a level of politico-economic activity that has not been suspected for the late Iron Age I [1300-1000 BCE] and early Iron Age IIA [1000-800 BCE]. . . . Many scholars have tended to dismiss trends toward political complexity (that is, state formation) occurring prior to the arrival of the Assyrians in the region in the later 8th century BCE. However, based on our work in the Hesi region, we believe these processes began much earlier.
Read more on ASOR: http://asorblog.org/iron-age-bullae-from-officialdoms-periphery-khirbet-summeily-in-broader-context/