This study aims to revisit the Constantinian texts concerning rescripts ad consultationem emissa. Do these rescripts have the value of precedents, applicable by analogy to similar cases, as they did during the classical period? Does the prince's reply merely constitute an advisory opinion that will leave the judge in control of the case, or does it constitute the final judgment? In June 318 Constantine seems to have taken a definite decision - the judge loses control over the case as soon as he refers it to the prince; the prince, supreme authority and sole interpreter of the law, is then the only one to pass final judgment.