The grandfather empires are Rome, Persia's Tahirid Dynasty, India's Chola Dynasty, China's Han Dynasty, and Axum. These five empires grew massive, with powerful and influential cultures. However during the 1200's a new mentality began to spread through these nations. This mentality known as the grandfather life caused people to believe that change was bad. Be it scientific or artistic, or any other change, people did not want what their grandfathers didn't have. This mentality cause the zeitgeist of these nations which in our OTL were great innovators to stand still in time.