Complex sentence: There is a romantic story of a blue dog swimming ashore from a shipwreck: the coat of this dog was so lovely that it was mated with all the female Wheaten Terriers in Kerry (or in all Ireland according to some), producing the Kerry Blue.
Split into simpler sentences: There is a romantic story of a blue dog swimming ashore from a shipwreck. The coat of this dog was so lovely that it was mated with all the female Wheaten Terriers in Kerry (or in all Ireland according to some) producing the Kerry Blue.