Upper Egypt was the heartland of the Kingdom at the peak of its power and influence, and the remains of its ancient cities form one of the most important and breathtaking archaeological collections in the world.
Lower Egypt was the heartland when the kingdom was declining.
mnli hypothesis: Lower Egypt was the heartland when the kingdom was declining. premise: Upper Egypt was the heartland of the Kingdom at the peak of its power and influence, and the remains of its ancient cities form one of the most important and breathtaking archaeological collections in the world.