China is one of the world's oldest civilizations, with a history spanning thousands of years. It has experienced periods of unity and fragmentation, with dynasties ruling the country for centuries at a time. The Qin dynasty unified China in 221 BC, followed by the Han dynasty, known for its cultural and technological advancements. The country saw periods of division and foreign invasions, including the Mongol rule under Kublai Khan and the Qing dynasty. In the 20th century, China underwent significant political and social changes, including the establishment of the People's Republic of China in 1949 under the leadership of the Communist Party. Today, China is a global economic powerhouse and plays a significant role in world affairs.