According to Chinese tradition, the first dynasty was the Xia, which emerged around 2100 BCE.[48] The Xia dynasty marked the beginning of China's political system based on hereditary monarchies, or dynasties, which lasted for a millennium.[49] The dynasty was considered mythical by historians until scientific excavations found early Bronze Age sites at Erlitou, Henan in 1959.[50] It remains unclear whether these sites are the remains of the Xia dynasty or of another culture from the same...