Complex sentence: After the second trial, he was sentenced to death and hanged, but somehow survived, and woke up on a table in front of Praetorius, who was at that time a medical student examining what he thought was a corpse.
Split into simpler sentences: After the second trial, he was sentenced to death and hanged, but somehow survived. When he woke up, he was lying on a table in front of Praetorius, who was at that time a medical student examining what he thought was a corpse.