With increasing wealth and power the kingdom grew south, taking parts of the Malay Peninsula from both the Malay and Burmese people. It also grew north at the expense of the Khmer Kingdom.
In the 1700s the city and kingdom reached their peak as the capital was home to about one million people. However in fighting and power struggles hurt the kingdom and in 1767 the kingdom fell to the powerful Burmese to their west.
In 1769 the Thais fought back, but now under the rule of Taksin, who began his attacks from Thonburi. In 1782 he became a monk and Rama I came to power as the new king, moving the capital to the city of Bangkok. In the 1790s the Burmese were driven out of Thailand.
Through the 1800s Siam (as the country was still called by foreigners) was approached by numerous countries to be colonized, given protection, etc. Despite neighbors falling to foreign powers, Thailand maintained independence for this period as the kings generally held good relations with outside powers and worked with them.
In 1932 this relative peace ended when revolts against the government arose and the government shifted from a monarchy to a constitutional monarchy. Shortly after the king abdicated and the government soon fell apart as numerous political groups formed and fought for power. This led to a stronger and stricter government, in which the military already held great power.
In 1941, during World War II, Thailand sided with the Japanese, partially because Thailand wanted to control French Indochina (Vietnam & Laos) and invaded at this time with Japanese support. Thailand lost and soon their support for the Japanese waned, especially since the Japanese granted these countries independence, instead of placing them under Thai rule. Later the Japanese wanted to use Thai lands to gain access to Burma and again the Thais accepted in order to avoid war. However relations between the two were always cautious as neither seemed to trust the other.
After WWII communist movements arose so Thailand turned to the United States to help protect them from an insurrection. This move worked as communism never made a true threat on the government and since then the United States and Thailand have shared very good relations.
In 1973 the government changed hands again, although the monarchy stayed in place. The people rose up and overthrew the primarily military government, but this didn't lead to peace and violence broke out sporadically and military intervention stepped in from time to time to secure peace.
In 2006 the people again revolted, this time against their prime minister who was abroad at the time. Again the change in government was peaceful and by 2007 the military stepped down and a new government took over. Another set of protests occurred the following year. Fortunately, none of these protests or coups have been joined with much or any violence and the country remains fairly stable, partially due to the king's steady presence and the people's respect for him.