For millennia corals were a marine enigma confounding classification and occupying a space between the animal and vegetable kingdoms. Ultimately their animal and symbiotic natures were recognized, and they remain the focus of intense fascination and research. The danger to seafarers posed by unseen underwater coral reefs led to their association with death and interment that has figured in literature, poetry, music and film. The bright redness of precious Mediterranean coral was associated with blood, including coral's gory origin in European and Indian mythology, and its place in religion. Corals have long been prized as jewellery and ornament, and were a feature of many Kunstkammer collections during the Renaissance. Seen as 'rainforests of the sea', coral reefs have become greenly emblematic of fragile marine biodiversity, warning of human-driven global climate change. This book uniquely treats the many manifestations of corals in biology and geology; how diverse corals came to figure in art, expeditionary accounts, medicine, folklore, geopolitics, and international trade; and corals as builders of islands and protectors of coastlines, and as building materials themselves. Exceptionally illustrated with a wide range of natural history images, underwater photographs and fine art, this book provides a unique resource for all interested in ocean environments and the cultures that have flourished there.