Conventional wisdom confers iconic status on the clause of England's Act of Settlement (1701) mandating secure tenure for judges. This paper estimates how the move to secure tenure affected the number of citations to judges' decisions, a measure of the quality of decisions. The empirics uses two new databases, on judges' biographies and on citations. Several strategies facilitate identification of the effect of secure tenure. A court-year panel permits difference-in-differences. Controls capture judges' human capital and amount of litigation. Historical evidence, tests of sensitivity to omitted-variable bias, and instrumental-variable estimates support the findings on the effects of tenure arrangements from fixed-effects OLS estimates. Secure tenure had a strong deleterious effect on associate-judge decisions and a comparatively smaller positive effect on chief-judge decisions. The effect of all judges having secure tenure was negative, large, and statistically significant. The iconic Act had an effect opposite to that universally assumed.