Complex sentence: Marcia, inorder to hide the princess, gave her to fellow wizard Silas Heap, who raised her as his own daughter Jenna as his own son Septimus died that same day after his birth.
Split into simpler sentences: Marcia, inorder to hide the princess, gave her to fellow wizard Silas Heap, who raised her as his own daughter Jenna. His own son Septimus died that same day after his birth.