Bangkok hadn't changed much during the reign of King Rama I to King Rama III. The citizen's lifestyle had been still like it was in Ayutthaya.

The defensive moats, city walls and forts had never been used because Siam changed the defense strategy by setting up the defence line out of the city instead of holding in the capital and hoping for the high tide to flood the enemy troops. In the reign of King Rama III, the influence of the Burma power slightly decreased, but the colonialism became a new threat.

In the reign of King Rama IV (King Mongkut), the westerners slightly increased in Bangkok. King Rama IV opened up Siam to a new era of modern progress and civilization, introduced new knowledge and technology from the West to Siamese society. Bangkok in this reign was more modernized than the previous reigns owing to modern roadways, new bridges, modern blocks, modern stemboats, modern rice mills, modern boatyards. Siam was forced to open the free trade with European countries and they built their consulates beginning from New Road down to Silom Road. The foreigners had favoured setting up their shops and banks near their consulates.

In the reign of King Rama V (King Chulalongkorn), his many Asia and Europe trips filled him with perceptions for the beauty of the great cities on the continent. For instance, The Mall in London that leads straight to Buckingham Palace, The Champs Elysees that leads straight to the Arc de Triomphe in Paris, and The Unter den Linden in Berlin. So he set himself the target of renovating Bangkok to attain the same level of beauty and order as those Western cities.

A significant expansion of Bangkok was seen during the reign of King Rama V. The modern reform was truely extensive, ranging from transportation and communication such as roads, railways, tramways, post, electricity, water supply, telephone, telegraph to public health, education and government administartion.

The early policy of road making was selective due to the short of Government funds, starting from roadways that run along the inner city wall, inner city moat and outer city moat. More roads were built running out of the city like the ray of the sun.

When the Government's revenue started increasing, King Rama V initiated to build the new palace, Dusit Palace, out of the north of thecity because of the dense of people in the Grand Palace.

And the most important roadway in the reign, Ratchdamnoen Avenue, was built to connect the Dusit Palace to the Grand Palace. This widest size and most beautiful road had brought, and still bring, dignity to Bangkok. Such important occasions as recieving and welcoming VIP guests to the city, trooping the colors ceremony, festival parades, and all important royal ceremonies and processions.

 

While the King build the new Dusit Palace, his relatives and the high ranking court officers also built their palaces and mansions around the Dusit Palace. These buildings were constructed in modern style.

The urban expanded to the east of the city. The market places started moving to the streets. The two-stroreies shophouses with the walkway colonade at the shopfront like as the shophouses in Singapore were built alongside of the city roads.

In this reign, the commercial real estate projects were emerged due to the Westerners and Chinese merchants demanded on beautiful roadside residences and shophouses. The Sathorn canal and Sathorn roads were built through the the land of Luang Sathornrachayuk who bought the land between Silom Road and Ban Tawai, and devided the land into small plots of 1 acre each on both side of Sathorn Roads for sale.

Chao Praya Si Suriwong and Phraya Siharat Dechochai followed the same footsteps. They built the road through their land from new Road to connect with Thanon Trong Road and built another road to connect with Silom Road. These roads were named Surawong Road and Decho Road.

Seven years later, 4 Phrayas and 1 Luang invested to allot and orchard plot between New Road and Klong Phadung Krungkasem Canal. They built the road down the middle of the plot and it was named Si Phraya Road in honour of the 4 Phrayas.

King Rama V led Bangkok to modernism with construction of many new roads, railways, office buildings, public utilities, and facilities including a tram service, electricity and running water service. One could turn in any direction and find modern development introduced by King Rama V.