Jack Black had another interesting sideline. When he caught any unusual coloured rats, he bred them, to establish new colour varieties. He would sell his home-bred domesticated coloured rats as pets, mainly, as Black observed "...to well-bred young ladies to keep in squirrel cages." Beatrix Potter is believed to have been one of his customers, and she dedicated the book Samuel Whiskers to her rat of the same name. The more sophisticated ladies of court kept their rats in dainty gilded cages, and even Queen Victoria herself kept a rat or two.
It was in this way that domesticated--or fancy--rats were established, though the fancy proper did not begin until Mary Douglas asked for permission from the National Mouse Club to bring her pet rats to an exhibition at the Aylesbury Town Show on October 24, 1901. Her black and white hooded Rattus norvegicus won "Best in Show," and the Rat Fancy was formally launched.
The original Rat Fancy lasted until 1931, as part of the National Mouse and Rat Club. The modern Rat Fancy was revived in 1976 with the formation of the National Fancy Rat Society, and the fancy spread around the world. Nowadays, fancy rats are accepted as perfectly normal pets and exhibition animals.