Complex sentence: The Shambles housed some three thousand badly wounded French troops, who had been evacuated from the Front and then all but abandoned weeks earlier and left unfed and untended with the dead and dying lying together on dirty straw.
Split into simpler sentences: The Shambles housed some three thousand badly wounded French troops, who had been evacuated from the Front and then all but abandoned. For weeks they had been left unfed and untended with the dead and dying lying together on dirty straw.