The Southeastern Asian Kingdoms
The Pagan Kingom
The Pagan Kingdom started around 840 CE, and was established by a group of people called the Burmans in what they called Burma, and we call Myanmar. The kingdom was in a optimal position similar to many very ancient civilizations in that it was next to a river in a river valley of the Irrawaddy River. The river's fertility made it ideal for the rice crop, similar to many other, further inland civilizations. King Anawrahta, who ruled from 1044 to 1077, 33 years, started to conquer lands around him in an effort to increase his land and give Burma trading ports and trade routes. He succeeded in 1057, uniting much of now Myanmar under his rule, bringing the whole kingdom prosperity. However, due to Marco Polo's trip to Burma in the late 1200's, the Yuan Dynasty, namely Kublai Khan, found out that the Burmans existed and immediately demanded tribute. The Pagan king refused and attacked the Mongols, a grave mistake. The Mongols crushed the Pagan army, so the Pagan king fled south, only to be stopped by one of his sons, which killed him, took the crown, then agreed to pay the Mongols. Because of this, the Pagan kingdom survived, although it lost it's power. To this day, some of the principles that the Pagans thought up still influence the Myanmar people today.
The Khmer Empire
To the southeast of the Pagan empire rose a new Empire rose in what is now Cambodia. They rose around the early 800s, late 700s, before the Pagans. By the early 800s, the Khmer began to conquer the kingdoms around them, reaching a high point in the time between 850 and 1220, in which they controlled much of the Southeast Asian mainland. They were influenced strongly by the Indians, and as such, the emperors adopted Hindu and Buddhist beliefs and ruled as gods, like the Egyptians and their pharaohs. In the empire's capital city was based on the shape of the Hindu universe, with a temple in the middle. In the temple were many splendorous temple complexes, the most splendorous being the Angkor Wat, of which still partially stands today. In the vast Angkor Wat complex built in the 1100s, it had a temple inside with walls and towers surrounding it. The central one supposed to be used as an astronomical observatory, stands about 200 feet tall. The Khmer could build such lush things mainly due to their rice farms, which were clever in design, allowing for millions of acres to be covered in rice farms. However, after 400 years, costly building projects and invaders caused the Khmer empire to finally decline.
The Trading Kingdoms
South of mainland, there were many kingdoms that sprung up in the islands. One of which, on the island of Java, was the kingdom of Sailendra, which flourished from 750 to 850. They focused mainly on agriculture and trade for their wealth. They did adopt Mahayana Buddhism, even making a monument at Borobudur. It had 9 terraced levels, like the 9 stages in the Buddhist spiritual journey.
On the island of Sumatra, the Srivijaya empire was established. Flourishing in the 600's all the way to the 1200's CE. At it's very height, the empire extended to Malay Peninsula and Borneo. The wealthy empire got it's power from overseas trade in the Malacca and Sunda straits. Knowing this, the rulers of Srivijaya empire ensured trade came to their empire. Like the Khmer empire, they adopted Hinduism and Buddhism, which they blended with their original beliefs. The Srivijaya capital at Palembang became a center of Buddhist learning, so much so that a Chinese monk declared that Buddhist students should come to Palembang to study for a year before studying at India. However in 1025, an Indian kingdom attacked, severely weakening the Srivijaya empire, and to make matters worse, other kingdoms gradually took over trade from the Srivijaya empire and eventually lead to an attack from a Muslim empire took over all the trade in the area, this lead to Islam spreading to the Srivijaya empire.
Unlike the other Southeastern Asian civilizations, Vietnam was influenced by China. By 111 BCE, the Han Dynasty had conquered the Vietnamese kingdom of Nam Viet, or what is now North Vietnam. For about 1000 years, the Chinese had ruled the region, what they called Annam, on and off, which forced them to adopt Chinese language, clothing and hairstyles. Confucianism and Daoism influenced the Vietnamese. The Vietnamese also adopted many features of Chinese government, including a bureaucracy and a Confucian-based civil service system. The Vietnamese also adopted Mahayana Buddhism, which resulted in a great deal of influence from Buddhist art and architecture. Despite being very influenced by China, they still keep some of their original aspects, like worshiping nature gods. To regain independence from China, two sisters Trung Trac and Trung Nhi raised an army and staged a rebellion in 39 CE that repelled the Chinese for a short while. When the Chinese came back anyway, the sisters drowned themselves. They are still known as heroes in Vietnam today. They finally succeeded at independence when the Tang dynasty fell in the 900's CE. In 939, they made a new kingdom of Dai Viet in the same place as Nam Viet. The new, independent kingdom sent tribute to China and even repelled the Mongols in the late 1200's