Lex Icilia de Aventino mount

The Lex Icilia of Aventino monte was a Roman law approved on the proposal of the tribune of the plebeian Lucio Icilio in 456 a. Being consuls Marco Valerius Maximus and Espurio Verginio Tricosto Celiomontano, that gave right to the town to build in Mount Aventine, dividing gratuitously among the people of the place the part not constructed already with just title and ordering to destroy what already constructed illegally or to the force. It was also established that this law could not be repealed by the Law of Twelve Tables.

wiki