As usual, you response is interesting.
Siam had control of North Burma, North Thailand, part of South China, Laos, North Vietnam, Hainan, Annam, Cochin China, Cambodia, Malaya and Singapore for over 500 years. Those areas have not had independent government for that long.
The Tais originated near the center of modern Thailand, creating many city-states and eventually moving north to create NanChao. NanChao was all of Southern China from India to TaiWan, for nearly 1000 years. The people spoke Tai, had a more refined culture than China built great fortresses, and grew rice. At that time, the Chinese were living in huts and developing, by borrowing. They borrowed many ideas from NanChao.
All Tai speaking people (including; Shan (Thai Yai), Payi, Tai, Dai, Black Tai, White Tai, Red Tai, Vieng, Tai Dioi (Yoi), Ahoms, Wu-Hu, Li, Lei, Loi, Man, Lolo, Karen, Lao and many, many othersi) are related to the Thai people. Most of them call their country Muang Tai (Tailand).
The native, non-Chinese, people of those areas still speak some variation of the Tai-Lao language. The foundation of the "Chinese language" of Canton (Cantonese) is Tai. Thai people who travel to Hong Kong are surprised that that can converse with some "Chinese" people living there. Those "Chinese" people wear Tai style clothing at home and have Tai customs.
This is true for Vietnam as well. Most of North Vietnam is Tai. (80% in some provinces). I have known a few Vietnamese who were half Tai and half Vietnamese and many more who are quarter French. A friend, Ngo Van Tai and I have discussed his Tai ancestry.
Tai influence is vast. China opening to the west, has allowed reachers to put the facts of Chinese history. Strangely enough, the oldest skeleton found in China is Falang.
Since reading your last message, I have been pondering your use of a word.
I had mentioned that Thai people are careful to be polite when they see a falang child with a Thai or Lao woman. You said that Lao people assume that the woman is a prostitute.
I have two problems with your statement.
First is assume. There is an old saying "to assume makes an ASS out of U and ME (ASSUME). Pretty much says it all. There are many reasons a woman might be with a falang child. As a caretaker, or the woman's grandmother might have married a Frenchman, or....... Genetic characteristics often resurface in latter generations.
Second is prostitute. I have seen "bar girls", "bar flies", "prostitutes" "whores", etc. in many countries. Thailand, by comparison, doesn't have any prostitutes..
This concept might take a deeper understanding. Americans have gone through many very tough centuries. French & Indian war, War of Independence, War of 1812, Mexican War, Civil War, 2nd Mexican War, Indian Wars, Spanish War, WW1, WW2, Korea, Vietnam, Iraq1 and Iraq2. We seldom have had true peace. This makes Americans independent and tough, but also bitter and mean. Americans like to enjoy life, but just under the happy surface is the past.
Here in Thailand, among a group of people that includes foreigners, I know who are the meanest, nastiest and usually toughest people. Thai meaness (JaiRai) is like the meaness of a an American child. Thai wars have been like schoolboy fights. Americans are raised on violence, so there is a core of trouble in our hearts. That is why we love carefree Thailand so much but that is why I question your use of the word prostitute.
In America a prostitute is typically a very mean, very bitter, tough, older woman. She says: What do you want to do? That will cost this much! Hurry up and finish! American prostitutes need the money for their pimp, their drugs and, always last, their kids - nothing for themselves or their parents.
Here, I have never seen a bitter woman who sold sex. Most 'bar girls' aren't 'mia chao' or 'gahlee'. All of them send money home to their parents and families. Bar girls are hired to attract drinking customers, nothing else. Some never go out, some will go out for a dinner, some will go out for fun, and sometimes they will have sex, but always to enjoy the person they are with. They are seldom 'forced' or 'coerced' into being sex slaves.
I said "seldom" because I have seen "short time bars", where women owe the bar owner some money and work off their debt by taking men to a bungalow out back. But even 'short time girls' don't always go with a man who wants them. Those girls usually owe money because someone 'sold' them to the bar. Their husband, their father or their brother needed money and traded their wife, sister or daughter for cash, a debt of honor for her, easy money for him. People who force women into that business are worse than pig shit (key moo).
I think you see the point. A prostitute is a mean, evil, bitter, angry women who only has sex for money and never enjoys her life. By comparison, Thailand doesn't have prostitutes.
It's not true that Tai people originated near the centre of modern Thailand. Tai people originated from China, and most moved to northern Laos. Remember, modern Laos still has a large population of Black Tai (Tai Dum) and Red Tai (Tai Daeng) people in the northern region, they've been there for thousands of years.
Also, Tai people have "light skin" because they are closely related to the Chinese. People who originated from central Thailand are generally dark, that's how they got their name "Thai daak lah", which is a common and rude saying in Lao language that means a "Thai person with a black butt."
When I said that Lao people assume that the woman is a prostitute, it's just a natural way that most Lao people think about Thai woman. Seriously it is not common for a Thai woman to caretake someone elses falang child, it is more likely her own old child.
The word "prostitute" basically means a woman selling sex for money. Thai woman may have sex to earn money for their parents or for their personal use, whichever way you look at it Thailand has prostitutes.