Analyses of constitutional conventions seldom include those conventions that concern relations between the judiciary and other arms of government. The focus tends to be on the conventions concerning the monarch, executive and legislature. This paper argues that an extensive set of constitutional conventions relating to the judiciary exist, and that an analysis of them reveals three insights about the nature of constitutional conventions and the nature of the judiciary. First, the judiciary’s authority, independence and impartiality is largely secured by means of constitutional convention. Second, the reliance on constitutional conventions points to the strength yet fragility of the judiciary’s constitutional position. Third, these constitutional conventions reveal that necessarily problematic for constitutional conventions to be modified or even destroyed. The paper analyses the executive’s duty to defend the judiciary from public attack in Australia, the UK and the United States.