The title of this book is taken from the words of Rodulf Glaber, a French monk and chronicler, who is noted to have exclaimed that at the beginning of the second millennium AD Europe was `cladding itself everywhere in a white mantle of churches'. He was clearly referring to the proliferation of church-building that was taking place but what was behind the explosion of Romanesque-style art and architecture across Europe at this time? Some have argued that apocalyptic fears and anxieties played their part in this phenomenon, however, these fourteen papers explore the subject from a much broader perspective. These papers, some of which were given at the International Medieval Congress held in Leeds in 2000, discuss aspects of the archaeological, architectural, art historical, liturgical, social and ecclesiastical evidence for changes in architecture, literature and art at the dawn of the second Christian millennium.