The cardinal bishops are the sole electors…

The cardinal bishops are the sole electors of the pope for the first time in the history of the Roman Catholic Church in the papal election following the death of Pope Nicholas II, held in San Pietro in Vincoli ("Saint Peter in Chains") in Rome on September 30, 1061, in accordance with Nicholas II's bull, In Nomine Domini.

Bishop Anselmo de Baggio of Lucca, a non-cardinal and one of the founders of the Pataria, is elected Pope Alexander II and crowned at nightfall on October 1, 1061, in San Pietro in Vincoli Basilica because opposition to the election makes a coronation in St. Peter's Basilica impossible.