What were these limits? What did the Constitutions allow the nobility do against the will of the king, assuming a king that wanted to uphold them? > nobody was

What were these limits? What did the Constitutions allow the nobility do against the will of the king, assuming a king that wanted to uphold them? > nobody was above it. It's not like there was an independent judiciary branch with the power to enforce that against the nobles or the king. Case in point: the king decided to eliminate them and he just went and did it.