In King Rama V’s reign, Siam encountered western colonization from powerful nations such as
British Empire and French Empire. To respond the colonization, the country needed to modernize the
administration that centralize power to the monarch. One of means was modernize usability of official
seals and royal coat of arms. So, this essay researches about development of using official seals and
coat of arms, these previously were administrational custom fromAyutthaya era, and modification of
them to be symbols of modern Siam.
