The Roman Catholic Church Rome, the center of Christianity and the seat of the Catholic Church, is a unique mix of majesty and beauty, combining history, faith, and art. This city's millennia-old history is embodied in each monument: basilicas, cathedrals, and catacombs. Art lovers will find museums full of masterpieces by great artists from all over the world. Rome has been inhabited since ancient times and was first founded as a city-state in 753 BC. It became one of the most important centers of Europe after the collapse of the Western Empire in 476 AD. The city now represents one-twelfth of the entire European Union population. The capital of Italy for nearly six hundred years, Rome is now only co-capital of Italy with Florence. But it still plays an important role politically and economically. Its influence on music, theater, literature, science, and technology -- not to mention architecture -- is evident everywhere in Europe today. Catholics are called "Roman Catholics" or "Welshy Christians." They share many beliefs with other Christians but also have unique practices of their own. For example, they celebrate Easter on a Sunday instead of Monday like most other Christians. They also use leavened rather than unleavened bread at Christmastime. Because Catholicism is a very large church, there are different types within it.