On the evening of 25 December , 44 cardinals gathered in the Sistine Chapel .
On the evening of 25 December , 44 cardinals elected Giovanni Angelo Medici as pope by acclamation , ending the longest conclave of the 16th century .
On the evening of 25 December , 44 cardinals gathered in the Sistine Chapel and elected Giovanni Angelo Medici as pope by acclamation , ending the longest conclave of the 16th century .