The article highlights a striking paradox: Petty’s Down Survey relied on Irish local knowledge to produce maps that enabled forfeiture and redistribution. Meanwhile, transplantation sought to regulate where many Catholic people could live, linking mobility, food and property to political control. This suggests that administrative techniques were not merely bureaucratic details but active instruments of settlement. How should we interpret the role of local guides, jurors and boundary experts in a process that depended upon their knowledge while potentially undermining their communities’ claims to land, and what comparisons might this invite with other early modern projects of conquest and mapping?