Early in Era 4, the two pillars of the Eurasian trading network, the Roman Empire and Han Dynasty China, collapsed. These weren’t the only societies to go into decline or break down during this era. As a result, European historians in particular have labelled much of this era a “dark age”. But was this true everywhere, or anywhere? Looking at Era 4 on a global scale, we see restructuring and rebui
License: CC BY-NC-SA by Khan Academy