Complex sentence: Arguably the most famous "Panorama" programme of all was the 1995 interview of Diana, Princess of Wales by Martin Bashir, which occurred after her separation, when she openly discussed the rumours surrounding her personal life.
Split into simpler sentences: Arguably the most famous "Panorama" programme of all was the 1995 interview of Diana, Princess of Wales by Martin Bashir. It occurred after the Prince and Princess of Wales had separated, and Diana openly discussed the rumours surrounding her personal life.