In the middle ages it begin after the collapse of Western Roman Empire around 476 ace last till roughly 1400 ace.
During Europe's middle ages other civilations such as china, byzantiam, the Islamic world, and the Africa city state. Their were no central government, no law or order.
When the Roman army disintegrated, there was no one to protect people, towns, and cities. There was conflict from invaders and amongest kings and chiefs. Their was also illiteracy. Also barbarians constanlly invaded and creating conflicts.