Complex sentence: Born in Cardiff, Wales in 1951 and started to fish at an early age about 12 years old, enjoying childhood fishing on the River Taff in Wales's which runs through the heart of the Principality.
Split into simpler sentences: Born in Cardiff, Wales in 1951, he started to fish at 12 years of age. He enjoyed fishing on the River Taff in Wales which runs through the heart of the principality.