The dean and assistant dean, also elected from among the cardinal bishops, are "called to exercise among the cardinal confreres a fraternal and fruitful presidency of primacy inter pares," he said.
He also thanked Sodano for his nearly 15 years of service in the role of cardinal dean and expressed his gratitude to the entire College of Cardinals "for their generous service to the Church and to my ministry as Successor of Peter."
In June 2018, Pope Francis changed the structure of the College of Cardinals, adding four curial officials to the rank of cardinal bishops.
The custom had previously been that the cardinal bishops were six cardinals from the Latin Church given a particular ceremonial title as the "titular bishops" of Rome's six ancient suburbicarian sees.
In modern times, cardinal bishops do not actually govern the suburban dioceses in the vicinity of Rome, though the custom of corresponding the rank of cardinal bishop to those dioceses had continued.
The pope's appointments in June 2018 broke with that custom.
Those eligible to be elected the next cardinal dean are Cardinals Giovanni Battista Re, Francis Arinze, Tarcisio Bertone, Jose Saraiva Martins, Pietro Parolin, Leonardo Sandri, Marc Ouellet, and Fernando Filoni, as well as Patriarchs Antonios Naguib, Bechara Boutros Rai, and Louis Raphael I Sako.
Sodano was a member of the Vatican's diplomatic corps beginning in 1959, including 10 years as apostolic nuncio to Chile. In 1988 he was appointed secretary for relations with states. He was secretary of state from 1991 until his resignation in 2006.