The more the power of Assyria grew, the greater became the role treaties played in its territorial expansion, as more and more nations exposed to its threat sought peace or alliance with it. Using a parable, one could say that from the early 7th century on, the empire grew by its own weight like a downhill-rolling snowball. The only major problem the expansionists in Nineveh faced was the internal stability of the empire. While external threats and local uprisings could under normal conditions be easily contained even by provincial governors, the capability to meet these challenges was seriously weakened at times of power struggles in the core, which paralyzed the normal functions of the state.
The Assyrian solution to the problem was to set up a mechanism geared to detect and nip all treacherous activities in the bud: pacts of loyalty obliging every Assyrian subject to accept and protect the sovereignty of the ruling king (or his heir apparent) and to immediately report any activities undermining this sovereignty to the king.
Such pacts seem to have been typically imposed after civil wars and at the official appointment of the heir apparent. All extant specimens are from the 7th century and they are therefore generally believed to represent a comparatively late development. However, a loyalty oath imposed on Assyrian citizens is already attested in an inscription of Šamši-Adad V dating from the 9th century B.C. (see below, p. XXVI), and it should be noted that stipulations typical of the 7th century 'loyalty pacts' also occur in the mid-8th century treaties from Sefire and other treaties not belonging to the category of 'loyalty pacts'. It would thus seem that the Assyrian royal house had already quite early recognized the gravity of the problem it was facing, and thus treaties comparable to the 7th century 'loyalty pacts' may well have existed considerably earlier.
Simo Parpola
Simo Parpola, 'Loyalty Pacts', Neo-Assyrian Treaties and Loyalty Oaths, SAA 2. Original publication: Helsinki, Helsinki University Press, 1988; online contents: SAAo/SAA02 Project, a sub-project of MOCCI, 2020 [http://oracc.org/saao/saa02/treatiesasinstrumentsofimperialism/loyaltypacts/]