Yoswadee Boon-Long was born in 1921 to a well-established Thai family. Her passion for 'sophisticated, timeless and elegant' couture began as early as the age of 15. Surrounded by a Thai cultured environment, western fashion was vaguely introduced to the population. Yoswadee pioneered to a Thai fashion revolution; she began to design and make dresses of such uniqueness and elegance, which she wore to attend balls. Many began to recognize her glamorous designs and before she knew it, she was already accepting countless requests to make exquisite gowns for her socialite friends. Soon afterwards, the requests began to multiply and so Yoswadee had to start business with her lavish couture.

At her early 20's she struggled to self-study fashion design and tailoring through various sources and was introduced to the Haute Couture fashion world in Paris. She officially began her first step into the fashion world by opening the Yoswadee fashion house in 1949.

Throughout the period of over 60 years Yoswadee's clients include members of a royal family, Thai first ladies and many in the upper echelons. Yoswadee has also held a fashion show with a world renowned French Jewellery Brand.

The brand concept of 'sophisticated, timeless and elegant' couture still lives up to the current designer and brand successor of Yoswadee: Pusdee Muntarbhorn, her daughter.