Complex sentence: The Jack Russell Terrier Club of Great Britain was established in 1974 as the parent club for the Jack Russell Terrier in the UK, which actively opposed recognition by Kennel Club (UK).
Split into simpler sentences: The Jack Russell Terrier Club of Great Britain was established in 1974 as the parent club for the Jack Russell Terrier in the UK. The club has actively opposed recognition of the Jack Russell Terrier by Kennel Club (UK).