 But from their commentary fundamental consequences for the Europe of the time are deduced, by the creation of a rich casuistry that covered a field of superior and more ample legal hypothesis from what was widely known until then.The foundation of this school of bolognian professors is due to Irnerius at the beginning of the 12th century.Disciples of his were Hugo de Porta Ravennate, Bulgarus, Jacobus de Boragine and Martinus Gosia, called "the four doctors" because of their wisdom and influences.