A.D. 618 - 907 -- The T'ang dynasty takes power and leads China into a period of prosperity and cultural achievement. The T'ang build no walls--just a few forts in the northwest.

A.D. 907 - 1279 -- After a series of revolts, the last T'ang emperor steps down, and China's government is in chaos for 53 years. The Song dynasty takes power and maintains peace by diplomacy. The Great Wall is crumbling, but the Song dynasty builds or repairs very few walls. Meanwhile, the Mongols invade and conquer much of Asia and Europe.

A.D. 1279 - 1368 -- The Mongols complete the conquest of China, and Kublai Khan becomes the first Mongol emperor.

A.D. 1368 - 1644 -- Hung-wu defeats China's last Mongol emperor and becomes the first emperor of the Ming dynasty. Much of the wall is in ruins by this time, and the Ming dynasty is responsible for major renovation and construction of the present-day Great Wall, a project that takes 200 years to complete. Many beacon towers and cannons are included in the Ming dynasty construction.

A.D. 1644 - 1911 -- The Manchus, a nomadic people who live north of the Great Wall in Manchuria, get through the wall, seize the Chinese capital city of Beijing, and set up the Qing dynasty. Although the Manchus are the type of invaders that the wall was created to keep out, the Manchus admire Chinese culture and adopt many Chinese traditions. During the Qing dynasty, the Chinese accept Manchuria as part of China, even though it lies beyond the Great Wall.

A.D. 1911 - 1912 -- The Manchu government is overthrown during a period of confused rioting. Sun Yat-sen of the Chinese Nationalist Party is appointed as president of a newly established Republic of China. Chinese military leaders, called warlords, command armies over their own areas in China. The power of the cruel warlords leads to chaos and great suffering for the Chinese people.

A.D. 1926 -- The Nationalists under Chiang Kai-shek unite with the Chinese Communists to defeat the warlords.

A.D. 1927 -- The Nationalists attack the Communists.