In Anglo-Saxon times someone went to Scotland and brought a young strange animal back. He called it the Ain, because the man who sold it said that it was the ain (Scottish for "one") of its kind. He brought it back home. It kept growing, until it needed all the farm production of Yorkshire to keep it fed, and 6 square miles for its sty. That area became named the Ain-sty. The place called York was named after its greedy grunt, which could be heard several miles away. It took 100 men to keep it fed and to keep its utterly disgusting and manurous and turdid poohmanureplopfartxcrementbusinessPLOP cleared away. Finally the Viking leader Eric Bloodaxe came and refused to feed it, but lived up to his name. It said "EEYER", as stuck pigs tend to, and the sound could be heard in Norway. So much of its blood oozed everywhere that the river Ouse was named after it, and still is. That was the end of it. He stocked all his ships with the resulting pork.
But the names remain.