Before becoming Thailand's capital in the late 18th Century, Bang Makok or "Place of Olives", now Bangkok, was an outlying district of Thonburi, a town founded as a trading post in the mid-16th century. Due to its proximity to Siam's capital, Ayuthaya, the town also developed military significance. In the 18th century a fortress was built on the banks of the Chao Phraya and a great iron chain hung across the river to block unwelcome arrivals.

The Chakri Dynasty was founded in the late 18th century. Shortly after, in 1782, King Rama I moved the capital to Bangkok on the other side of the river, believing it was an easier location to defend. Using the labor of thousands of Khmer prisoners of war, city walls were built, the canal system was expanded, and new temples were erected by artisans from Ayuthaya. When the construction of the new capital was finished in 1785, it was given a new name, a tongue-twister comprising 164 letters which referred modestly to divine gems, unconquerable lands and divine shelters. The name was mercifully shortened to Krung Thep or "City of Angels", but the city is still known as Bangkok to most of the outside world.

The first half of the 19th century in Bangkok saw a flurry of temple construction under the rule of Rama III. The definitive moment of his successor's reign was the building of the city's first road alongside the river in 1861. More roads were soon added and, well before the turn of the century, horse-drawn carriages and rickshaws had replaced watercraft as the favored mode of urban travel.

During the first decades of the 20th century the city grew in all directions and numerous roadways were added to carry new motorized forms of transport. In 1932 Thailand established a constitutional government. In World War II the Japanese briefly occupied parts of the city. Following the war Bangkok quickened its pace towards modernization. From the mid-1960s the city became a favorite 'rest and recreation' spot for American troops involved in the Vietnam conflict. The sex trade continues to this day in the form of various nightclubs and massage parlors. After riding a double-digit economic boom through the 1980s, Bangkok was hit hard by the economic crisis that swept Asia in 1997.