The study of constitutional conventions is anchored in an assumption that has so far remained unchallenged: Commonwealth courts will recognize and employ conventions but never enforce them. We show in this Article that the dominant view today is doubly mistaken: there is no such shared “Commonwealth approach” to the treatment of constitutional conventions nor do Commonwealth courts refrain from enforcing conventions. Drawing from Canada, India and the United Kingdom, we disrupt the foundations of the scholarly understanding of conventions by demonstrating that Commonwealth courts have recognized, employed and indeed also enforced conventions. Beyond this new discovery, we make the normative claim that Commonwealth courts sometimes should enforce conventions, an additional contrast between the dominant view and ours. We argue that courts should act as executors of the will and judgment of constitutional actors, and limit themselves to enforcing only power-shifting conventions, which transfer power from those who have legal power to those who can legitimately wield it. This new role of an executor court brings clarity, stability and predictability to the exercise of official powers that are rooted in constitutional convention rather than constitutional law.