Ch'in Dynasty China
The Ch'in Dynasty is the one which gave its name to China. The first Ch'in emperor, in 221 BC, was Ch'in Shih Huang Ti. He started out as the king of a smaller state, but he was able to force all the other states to accept his rule too, so then he became the emperor of all China. To show that he was the emperor, and more important than the other kings, he built big palaces and had very elaborate court ceremonies in his capital city of Xianyang. And, to show that China was all one empire now, Ch'in made everyone use the same letters to write with and use the same kinds of weights to measure things with, all over the empire.
Ch'in didn't trust the other kings whom he had conquered, so he didn't
let them run anything. Instead, he chose his own assistants and sent
them out as governors and judges for each part of his empire. And, so
that he could keep an eye on the kings and their families, he made them
leave their homes and come live in the capital city with him, and help
him there. That way they couldn't revolt against him.
Ch'in also got together a huge army to keep the kings from revolting against him. And when he didn't need it for revolts, he kept the army busy defending the empire and making it bigger and bigger. Soon China reached from Mongolia in the north to Vietnam in the south.
The biggest danger to China was the people who lived in Mongolia and Siberia, who often tried to invade China. A lot of the kings in northern China had already built walls along their kingdoms to keep out these invaders. Ch'in ordered his army to join up all these little walls to make the Great Wall of China. The wall ended up being 1,500 miles long (2400 kilometers)! That's almost as long as the United States' border with Mexico (most of which doesn't have a wall.)