Complex sentence: Relenting, Augustus removes Postumus for a double named Clemens and secretly writes a will restoring Postumus as his heir, but Livia manages to discover this and poisons Augustus.
Split into simpler sentences: Relenting, Augustus removes Postumus for a double named Clemens and secretly writes a will restoring Postumus as his heir. But Livia manages to discover this and poisons Augustus.