Complex sentence: However, William Hillcourt in "Two Lives of a Hero" (1964) added the fourth Rodney brother, Simon Rodney and later supported this by evidence from the oldest Rodney brother, then the 8th Baron Rodney.
Split into simpler sentences: However, William Hillcourt added the fourth Rodney brother, Simon, in "Two Lives of a Hero" (1964). This evidence was supported by the oldest Rodney brother, then the 8th Baron Rodney.