The pope, otherwise known as the bishop of Rome, lives in the Vatican. Of all the sovereign states in the world, Vatican City is the smallest and encompasses an area of approximately 109 acres. The one grand church in Vatican City called the Basilica of St. Peter is the master church for all Catholics and is the largest church in the global Christian community. About 1,100 people live in this city and about 4,200 work there every day. Not only is the Vatican the home of the head of state, the pope, it is also the home of a vast collection of religious art and contains the largest library of ancient sacred books dating as far back as the 1st century A.D.