Bishops, schism, and the SSPX

With the society announcing plans for an illicit consecration, what is the history and the law?

Archbishop Marcel Lefebvre performing an act of consecration without papal mandate, and of schism.

After the Society of St. Pius X announced this week that it plans to consecrate a bishop without a papal mandate in July, the prefect of the Dicastery for the Doctrine of the Faith has said Vatican talks with the society will continue, towards a goal of reg…