Around 2055 BC , Mentuhotep II , the son and successor of pharaoh Intef III defeated the Herakleopolitan pharaohs and reunited the Two Lands , thereby starting the Middle Kingdom .
Around 2055 BC , Mentuhotep II , the son and successor of pharaoh Intef III defeated the Herakleopolitan pharaohs and reunited the Two Lands . This was the start of the Middle Kingdom .