Srilanka, May 8 -- Roman Catholic Cardinals were set to cast a first round of ballots for a new pope on Wednesday in the Vatican's Sistine Chapel, gathering under the soaring frescoes of Renaissance masters and a blanket of intense seclusion as they elect the next leader of 1.4 billion faithful.

The largest number of voting cardinals in history, 133, are embarking on the first papal conclave in more than a decade, just over two weeks after the death of Pope Francis set in motion the process of choosing his successor.

It comes at an uncertain time for the church, which is facing difficult decisions about its future direction, strained finances and a reckoning over past sex abuse scandals.

Cardinal Pietro Parolin of Italy has emerged as...