The first conclave was proposed by the first Pope, St Peter-Acts 1 : 20-26 ; For,” said Peter, “it is written in the book of Psalms,
” ‘May his place be deserted ;
let there be no one to dwell in it,
and,
” ‘May another take his place of leadership.’
Therefore it is necessary to choose one of the men who have been with us the whole time the Lord Jesus went in and out among us, beginning from John’s baptism to the time when Jesus was taken up from us. For one of these must become a witness with us of his resurrections.”
So they proposed two men : Joseph called Barsabbas and Matthias. Then they prayed, “Lord, you know everyone’s hear. Show us which of these two you have chosen to take over this apostolic ministry, which Judas left to go where he belongs.” Then they cast lots, and the lot fell to Matthias ; so he was added to the eleven apostles.
In view of above, the conclave have expanded from eleven apostles to 135 electors universally. This is the conclave in the history of the church. These electors represent 71 countries : Europe [51], Asia [23], the Americas [37], Oceania [5] and Africa [17].