How many years did each dynasties last?

The duration of dynasties can vary widely based on historical context. For example, the Qin Dynasty in China lasted about 15 years (221-206 BCE), while the Han Dynasty lasted approximately 400 years (206 BCE-220 CE). In contrast, the Roman Empire, which is often considered a dynasty in a broader sense, lasted about 500 years if taking into account the Western Roman Empire's fall in 476 CE, while the Eastern Roman Empire (Byzantine Empire) continued for nearly another thousand years. Each dynasty's length is influenced by factors such as political stability, economic conditions, and external pressures.