Complex sentence: Two companies advanced on Gallipoli at behind a creeping barrage and a Stokes Mortar bombardment and reached the farm buildings, only to be shot down by a hidden machine-gun from behind and caught in cross-fire from the farm buildings and a derelict tank.
Split into simpler sentences: Two companies advanced on Gallipoli at behind a creeping barrage and a Stokes Mortar bombardment. The attackers reached the farm buildings, only to be shot down by a hidden machine-gun from behind and caught in cross-fire from the farm buildings and a derelict tank.