Complex sentence: He was also a good friend of the Prince of Wales, later who later became King George III. Lyttelton received his pension through his estranged father, and because of his parentage and outstanding ability he also held privileged positions in society.
Split into simpler sentences: He was also a good friend of the Prince of Wales. Thomas received his pension through his estranged father, and because of his parentage and outstanding ability he also held privileged positions in society.