Pope resignation leaves Catholic world in shock

VATICAN CITY (Reuters) - Pope Benedict left the Catholic world in shock after becoming the first pontiff since the Middle Ages to resign his office, saying that failing strength had left him unable to lead the church through a period of relentless change and turmoil.

The 85-year-old pontiff announced his abdication as leader of the world's 1.2 billion Catholics in a speech delivered in Latin, the universal language of the church, to cardinals meeting in the Vatican's Apostolic Palace.