Complex sentence: After his art education finished, he moved to London and became a leading exhibitor with several societies including the Royal Institute of Oil Painters (R.O.I.) and Royal Society of Portrait Painters (R.P.).
Split into simpler sentences: After his art education finished, he moved to London. He became a leading exhibitor with several societies including the Royal Institute of Oil Painters (R.O.I.) and Royal Society of Portrait Painters (R.P.).