There is no real chief of staff by that title. There is, however, a camarlengo who assists the pope and takes over most of the popes administrative duties should the pope die. The current Camerlengo to Pope Francis (2014) is Jean-Louis Tauran.
The pope's chief of staff, called the Camerlengo
Pope Francis is pope number 266.
Since Pope Francis is the first and only pope by that name, there is no need for a number after his name. If a pope in the future also decides to take the name Francis, he will become Pope Francis II and then the original Pope Francis will become Pope Francis I.
Pope Francis is the reigning pope in 2013.
Only Pope Francis and God know what Pope Francis thinks.
No, Pope Francis does not smoke.
Pope Francis has not been succeeded at the time of this answer.
Pope Francis I is from Buenos Aires, Argentina.
Pope Francis was elected pope in the Sistine Chapel.
The current Pope Francis is from Argentina.
Pope Francis, elected in 2013, is the 266th pope.
Chief of Staff is a proper title.