Recently, advancements in Islamic legal studies have uncovered much of the institutional and normative roots of premodern Islamic law. However, the origins and evolution of penal structures in the first century of Islam have not been thoroughly examined. Mathieu Tillier and Irene Scheinder discuss the existence of criminal prisons (sijn al-jarim) during the eighth and ninth centuries. Beyond containment and control, these jails also served as a means of judgement and punishment for the offenders. Given the fact that prisons had a minimal presence in Arab societies before the advent of Islam, what prompted the emergence of such inquisitorial procedures? Late Antique Eastern Roman and Sasanian regimes utilized imprisonment as a penalty. In contrast, pre-Islamic and early Islamic civilizations largely viewed detainment as the primary purpose of these sites. Remarkably, a radical expansion in the function of incarceration ensued during the seventh and eighth century under the Umayyad and Abbasid Caliphates. Penitentiaries became punitive spaces for torture, ad hoc lashings, and lengthy sentences as expressions of the state’s legal authority. This momentous development was not an inevitability. Despite Europe’s Roman heritage, these institutions and penalties only materialized centuries later in premodern Latin-Christian societies, like late medieval Italy and early modern France. This driving need must have demanded a legal-political transformation, propelled by dramatic social and political factors. I argue that along with expanding central authority and notions of sovereignty at the expense of tribal dynamics and provincial autonomy, rapid urbanization and population growth gave rise to criminal prisons. Utilizing a wide range of sources such as literary narratives, political and legal treatises, and papyri records allows for a more three-dimensional portrait of this penal trajectory. Umayyad and Abbasid-era authors, such as Abd al-Hamid al-Katib (d. 749/750) and al-Tabari (d. 923) are integral to my argument. Aligning these depictions with secondary scholarship on Late Antique prisons and medieval European prisons, I can better perceive the principal dynamics that give rise to incarceration as a disciplinary measure.