The creation of the Registry of Deeds is striking because it combined commercial security with a confessional political order. By making property claims visible and prioritising registered transactions, the system could aid lenders and purchasers, yet it also strengthened Protestant control after confiscation while leaving Catholic access constrained. The article suggests administrative innovation was not technical: it shaped who could convert land into security, inheritance and influence. How should we interpret the Registry’s legacy: chiefly as an archive improving legal certainty across Ireland, or as a mechanism whose benefits remained inseparable from unequal distribution of power at its historical foundation?