Complex sentence: But one night, when gas was released from Nelsons corpse which caused the lid of the barrel to fall of, the guard fled and when he returned only half of the brandy had been left by the thirsty British seamen.
Split into simpler sentences: But one night, released from Nelsons corpse caused the lid of the barrel to fall off. The guard fled and when he returned only half of the brandy had been left by the thirsty British seamen.