By the end of the 19th Century, the breed had declined so much that in 1900 there was only one female to be found in the town of Rottweil. But the build up to the World War I saw a great demand for "police dogs," and that led to a revival in interest for the Rottweiler. Its enormous strength, its intelligence, and its ability to take orders made it a natural weapon of war. From that time, it has become popular with dog owners, and in 1935 the breed was officially recognized by the American Kennel Club. In 1936, Rottweilers were exhibited in Britain at Crufts. In 1966, a separate register was opened for the breed.