The pope is simultaneously the absolute sovereign of the Vatican City State and the head of the Roman Catholic Church throughout the world. Since 1984, the pope has been represented by the cardinal secretary of state in the civil governance of Vatican City. In administering the government of the Vatican, the pope is assisted by the Pontifical Commission for the Vatican City State. Religious affairs are governed under the pope's direction by a number of ecclesiastical bodies known collectively as the Roman Curia.
The Pontifical Commission consists of seven cardinals and a lay special delegate, assisted since 1968 by a board of 21 lay advisers. Under the commission are the following: a central council (heading various administrative offices); the directorships of museums, technical services, economic services (including the postal and telegraph systems), and medical services; the guard; the Vatican radio system and television center; the Vatican observatory; and the directorship of the villa at Castel Gandolfo, the traditional summer residence of popes.
Much of the work of the Roman Curia is conducted by offices called sacred congregations, each headed by a cardinal appointed for a five-year period. These are the Sacred Congregation for the Doctrine of the Faith (responsible for faith and morals, including the examination and, if necessary, prohibition of books and other writings), the Sacred Congregation for Bishops (diocesan affairs), the Sacred Congregation for the Eastern Churches (relations between Eastern and Latin Rites), the Sacred Congregation for the Sacraments, the Sacred Congregation for Divine Worship, the Sacred Congregation for the Clergy, the Sacred Congregation for Religious Orders and Secular Institutes (monastic and lay communities), the Sacred Congregation for the Evangelization of Peoples (missions), the Sacred Congregation for the Causes of Saints (beatification and canonization), and the Sacred Congregation for Catholic Education (seminaries and religious schools). There are also secretariats for Christian unity, non-Christians, and nonbelievers, and there are permanent and temporary councils and commissions for various other functions.
A pope serves from his election until death. On his decease, the College of Cardinals is called into conclave to choose a successor from their number. The usual method is to vote on the succession; in this case, the cardinal who receives two-thirds plus one of the votes of those present is declared elected. Pending the election, most Vatican business is held in abeyance.
Before the reign of Pope John XXIII, the size of the College of Cardinals was limited to 70. Pope John raised the membership to 88, and his successor, Pope Paul VI, increased the number to 136. Paul VI also decreed that as of 1 January 1971, cardinals would cease to be members of departments of the Curia upon reaching the age of 80 and would lose the right to participate in the election of a pope. In 2001, Pope John Paul II created 44 new cardinals, and the number of cardinals in the college at that time was 184, representing 68 countries.