Complex sentence: Combat was a brown horse bred by his owner John Arthur Dewar who inherited his thoroughbred racehorses from his uncle the Scottish whisky distiller Thomas Dewar, 1st Baron Dewar.
Split into simpler sentences: Combat was a brown horse bred by his owner John Arthur Dewar. Dewar inherited his thoroughbred racehorses from his uncle the Scottish whisky distiller Thomas Dewar, 1st Baron Dewar.