Ayutthaya Period ( 1350 - 1767 )
There are 3 types of dressing styles in Ayutthaya period. At that time, there were many wars, and the costumes continue changing after each wars.
There are 3 steps of dressing styles in Ayutthaya.
1. The costume under royal law, this type is a costume for senior government officer and for citizens who are very rich can wear this type costume. Men wear round collar shirt with loincloth The women wear cotton cloth, and breast cloth that wrap over one shoulder around chest and back, and some wear shirt.
2. The villager costume (The middle era of Ayutthaya), the men in the northern part wear loincloth and have long hair, but the southern part men have short hair. Since the king Narai era, Thai men have to changed their hair style into Mahadthai. Women still have long hair, and wear breast cloth.
3. War period (The late era of Ayutthaya), men and women have to declare wars. Women must have a short hair in order to disguise as men and easier to flee. Costumes are designed for wearer in order to move easier. Women wear cloth that cross their chest and tied up over their neck. Men costume did not changes from earlier.
Reference (Thai) : http://www.human.cmu.ac.th/home/hc/ebook/006216/006216-02.pdf