This article points to the 1820s as a crucial period that saw a great reversal in the location of sovereignty in Belize. The article employs two inflection points—first, an 1822 case of ‘Indian’ slaves from Mosquito Shore, and second, slave desertion in 1825—to point to unprecedented challenges to settler sovereignty over slavery in Belize that arose during the 1820s. While British amelioration allowed the metropolitan government to bring frontier and borderland regions within its legal purview, thus challenging settler autonomy, the concurrent event of Central American emancipation provided enslaved people in Belize additional opportunity to desert their masters at a moment when restitution of runaway slaves became increasingly difficult. Yet, this essay is about more than just the fracturing of settler sovereignty over slavery. Rather it also illuminates how settlers responded to these challenges by using force, diplomacy, and the print media. The settlers’ most potent response was in portraying Belizean slavery as ‘benign,’ creating a surprisingly robust narrative that would endure for generations. The essay illuminates how emancipation and imperialism remained inextricably linked in borderland areas such as Belize, which straddled the boundaries between Spanish America and the British Caribbean.