Precedents, standards and customs of the time and place were recognized by the courts.
And become the force of law effectively, if the court holdings were published at the appellate court level, unlike Civil Law nations, unless reversed by statute. The balance of power changed. I am a big fan by the way of court legal precedent becoming law, until reversed. Fact patterns are so variable, that without such "law," we would get individual courts deciding cases in more idiosyncratic ways, case by case. That is not "good." It creates more uncertainty as to what the law is, in particular fact patterns. Uncertainty as to what the law is, creates more risk. Risk is a cost, economically and otherwise. That is why Civil Law nations are moving towards the concept of court legal precedential authority. To do otherwise, incurs more risk costs. It also runs increased risk of folks in similar situations, getting different legal results. That is unjust.