Complex sentence: He served in the Imperial Light Horse and showed courage in battle when, at the Siege of Ladysmith, he was the second man to ride into battle, and rescued a comrade from heavy gunfire at Hlangwane by carrying him for 1.5 miles.
Split into simpler sentences: He served in the Imperial Light Horse and showed courage in battle. He was the second to ride into battle at the Siege of Ladysmith, and he carried a injured comrade through heavy gunfire at Hlangwane for 1.5 miles.