Complex sentence: Although the counter-attack was ultimately successful in breaking through the Japanese blocking force, it also forced a large group of Australians off the track, and over several days large numbers trekked through the jungle in an effort to rejoin their units.
Split into simpler sentences: Although the counter-attack was ultimately successful in breaking through the Japanese blocking force, it also forced a large group of Australians off the track. Over several days large numbers trekked through the jungle in an effort to rejoin their units.