Bison roamed across Britain for hundreds of thousands of years along with wooly mammoths and saber-toothed cats. But the last of them died out 6,000 years ago and the last bisons in Europe very nearly died out 100 years ago until people worked with a small number of captive bison to build a growing and very carefully managed herd. Now a small number of these gentle giants have been relocated to an ancient forest near Kent that had become a monoculture pine plantation. There are signs that the new immigrants are beginning to naturally restore the area to its ancient splendor.