As ice retreated from Britain 15,000 years ago, a host of large mammals including reindeer, wild horses, wooly mammoths, moose, wolves, brown bears, lynxes and wolverines established itself in Britain. The largest surviving wild land mammal today, the red deer, the largest contemporary land carnivore, the badger and another 65 or so extant wild mammals included about a quarter of the wild mammals that have been introduced in the last 15,000 years. The contemporary fauna, however, is largely dominated by domestic animals, such as cattle, sheep, pigs and humans. This book explores the fate of the large extinct species, as well as how, why, and when the introduced species appeared.