This history of Nong Khai can be traced back to the Haw Wars between 1865 and 1890. During that time, Chinese warriors known as Flag Gangs plundered large areas of Laos and Tonkin (now northern Vietnam).The Chinese Black Flags and their rival Yellow Flags set up bases in these areas.

To aid its neighbors, Thailand (then known as Siam), sent military forces to Nong Khai.

In 1875, the first of these forces crossed the Mekong river to engage the Flag Gangs, succeeding in capturing the base at Chiang Kham. Before they could be defeated, the remaining Flag Gangs retreated to the mountains.

To maintain security in the area, the Siamese force remained in Nong Khai. From there, a series of small towns emerged to form the boundaries of modern-day Nong Khai. These towns included Pakho, Phai, Wiang Khuk, and Phran Phrao.

Many temples from these ancient towns still survive to this day, particularly on the Tha Bo to Si Chiang Mai route along the Mekong river.

Up until that time, the area was not yet known as Nong Khai. That name was given to the area during the time of King Rama III.

When King Rama III ruled Vientiane during the Rattanakosin era, a rebellion was staged against the King by Chao Anuwong. Thao Suwothanma, the ruler of Yasothon, helped King Rama’s army crush this rebellion.

In gratitude, King Rama made Thao Suwothanma the ruler of a new town that would rise at the right bank of the Mekong River were the town known as Phai was located.

The new town became known as Nong Khai, which got its name from a huge pond located west of the town.

Today, Nong Khai is basically a border town that revolves around the traffic of such locations. The city has emerged as a popular tourist destination in recent years and, today, has the full backing of the Tourism Authority of Thailand.