Welcome to the Palais des Papes in Avignon, a colossal monument that stands as the largest Gothic palace ever built in Europe. As you look up at its towering walls, you are seeing a place that, for much of the fourteenth century, was the center of the Western Christian world. It was in thirteen hundred and nine that Pope Clement the Fifth fled the violent unrest of Rome to settle here in Avignon, beginning a period often called the Babylonian Captivity of the Church. For nearly seventy years, seven successive popes and two antipopes governed from within these very walls, transforming a provincial town into a grand cultural and political capital. Today, this UNESCO World Heritage Site covers fifteen thousand square meters—roughly the size of four individual Gothic cathedrals combined. Take a moment to breathe in the history of this most well-fortified house in the world, as described by the medieval chronicler Froissart, as we prepare to step back into the era of papal splendor.