Incarceration (publica custodia) in facilities such as the Tullianum was intended to be a temporary measure prior to trial or execution.
[1] More extended periods of incarceration occurred but were not official policy, as condemnation to hard labor was preferred.
[2] Detention is mentioned in the Twelve Tables, Rome's earliest legal code (mid-5th century BC), and throughout juristic texts.
[3] "Detention," however, includes debt bondage in the early Republic;[4] and the wearing of chains (vincula publica), mainly for slaves and convict labor.
Increasingly during the Imperial era, a long-term sentence, often for life, was hard labor at the mills, mines, or quarries,[5] which might be privately or publicly owned.
[6] On large commercial agricultural estates (latifundia, sometimes compared to plantations), enslaved laborers who had offered resistance were kept chained in semi-underground places of imprisonment called ergastula.