Complex sentence: The Pharaoh of the Exodus is the pharaoh (king) who ruled over ancient Egypt at the time of the Exodus-more precisely, it is the question of who this pharaoh might have been.
Split into simpler sentences: The Pharaoh of the Exodus is the pharaoh (king) who ruled over ancient Egypt at the time of the Exodus. More precisely, it is the question of who this pharaoh might have been.