It would be interesting to see what specific quotes or sections of primary sources people have found most helpful. Also, are there specific inscriptions or archaeological finds that noteworthy? My own research last week discovered this oath on allegiance to the emperor:
This is the oath taken by the inhabitants of Paphlagonia and the Romans who do business among them. ‘I swear by Zeus, Earth, Sun, all the gods and goddesses and Augustus himself that I will be favourably disposed to [Cae]sar Augustus and his children and descendants all the time of my [life] in word and deed and thought… Whatever I may see or hear being said or plotted or done against them, I will report it and I will be the enemy of the person who says or plots or does these things . . . If I do anything contrary to this [oath] . . . I pray that there may come on me, my body and soul and life, destruction, total destruction until the end of all my line and of all my descendants…’ In these same words this oath was sworn by all the [inhabitants of the land] in the temples of Augustus throughout the local districts [of Paphlagonia] by the altars [of Augustus].
R. K. Sherk, The Roman Empire: Augustus to Hadrian (1988). Another version of this same oath is offered below:
What an extraordinary text describing the allegiance of some to the emperor!
Imperator Caes[ar,] son of the god, Augustus the twelfth consulship, third year (of the province, 3 BC), on the day before the Nones of March in Gangra in [camp(?)], the oath completed by the inhabitants of [Pa]phlagonia [and the] R[omans] who do business among them; I swear by Zeus, Earth, Sun all the gods [and] goddesses, and Augus[t]us himself that I will be favourably disposed toward [Cae]sar Augustus and his children and descendants all the time of my [life] in word and deed and thought, considering as friends those whom they may consider (friends) and holding as enemies those whom they may judge to be (enemies), and for things that are of interest to them I will spare neither my body [nor] my soul nor my life nor my children, but in every way for the things that affect them I will undergo every danger; and whatever I might perceive or hear against them being said or plotted or done, I will report it and I will be an enemy to the person saying or plotting or doing [any of] these things; and whomever they may judge to be their enemies, these, on land and sea, with arms and steel will I pursue and ward off. If I do anything contrary to this [oath] or anything not in agreement with what I have sworn, I pray that there may come upon myself, my body and soul and life, my children and all my family and whatever is of use to us, destruction, total destruction till the end of all my line [and] of all my descendants, and may neither the [bodies] of my family or of my descendants by earth or [sea] be received, nor may (earth or sea) bear fruit [for them.] In the same words was this oath sworn by all the [inhabitants of the land] in the temples of Augustus throughout the districts (of the province) by the altars [of Augustus.] And likewise the Phazimonians living in what is [now] called [Neapo]lis [swore the oath,] all of them, in the temple of Augustus by the [altar of] Augustus. [*]