and the 40,000 of Mon people migrated through the Three Pagodas Pass to Siam. King Rama II sent his young son Prince Mongkut to welcome the Mons at Kanchanaburi on that occasion. Chinese immigration was the greatest contributor to the population growth of Central Siam. They were increasingly integrated into Siamese society over time. Crawfurd mentioned 31,500 male registered Chinese taxpayers in Bangkok in his visit in 1822. Malloch stated that, during his stay in 1826, 12,000 Chinese people arrived in Siam annually from Guangdong and Fujian Provinces. The Chinese settlers were adorned with special treatment by the royal court. Unlike other ethnicities, the Chinese were spared from corvée obligations and wartime drafts on the condition that they paid a certain amount of tax known as Phuk Pee (). Once the tax was paid, they were given an amulet to be tied around their wrists as the symbol. The first Phuk Pee was conducted in the reign of King Rama II. The Chinese settlers played a very important role in the development of Siamese economy in the early Bangkok period. The unrestricted Chinese were free to move around the kingdom, serving as commercial middlemen and became the first ‘bourgeoisie’ class of Siam. Society Despite important political changes, the traditional Siamese society in the early Rattanakosin period remained largely unchanged from the Ayutthaya period. Theravada Buddhism served as the main ideology on which the societal principles were based. The king and the royal dynasty stood atop of the social pyramid. Below him was the common populace who were either the Nai (), who were the leader of their subordinates and held official posts, or Phrai commoners and That slaves, though there were substantial degree of social mobility. Ethnic immigrants became Phrai and That also, with the exception of the Chinese who had paid the Phuk Pee tax. Sakdina was the theoretical and numerical rank accorded to every men of all classes in the kingdom, except the king himself, as described in the Three Seals Law. Sakdina determined each man's exact level in the social hierarchy. For example, the Sakdina of the nobility ranged from 400 rai to 10,000 rai each. The Sakdina of a basic Buddhist monk was 400 rai. The Sakdina of a slave was 5 rai. The traditional Siamese society was roughly stratified into four distinct social classes; The royalty, Chao; including the king and the royal family The