The papal conclaves of August 1978 and of October 1978 were respectively convened to elect a pope, the leader of the Catholic Church, to succeed Paul VI and John Paul I following their respective deaths on 6 August 1978 and on 28 September 1978. In accordance with the apostolic constitution Romano Pontifici eligendo, which governed the vacancy of the Holy See, only cardinals who had not passed their 80th birthday on the day on which the conclave began (in these cases, cardinals who were born on or after 25 August 1898 for the first conclave, and on or after 14 October 1898 for the second conclave) were eligible to participate. Although not formal requirements, the cardinal electors invariably elected the pope from among their number and did so by secret ballot (Latin: per scrutinium). Due