Public law aims to offer the essential foundations of public law rules. In the first, constitutional history of Italy, from 1848 since now. In the second, Eu institutions and their influence on italian government. In the third, the way in which rules can take effort in Italy, from constitution, to law and regulaments, even if they are not made by the State but by other agencies. In the fourth, it gives a survey about constitutional agenzie, like Parliament, Government, Chief of the State, Constitutional Court, and the People, including the functions of each one.