of King Rama I, Phrai luang served alternating two months and became alternating three months in subsequent reigns. Royal services included garrison maintenance and drills, palace and temple constructions, participation in royal ceremonies and warfare. Distributed servants, Phrai som (); Phrai som were granted by the king to the princes according to the ranks and honors of the princes. The Phrai som served under services of their princes. However, due to the manpower shortage, King Rama I ordered the Phrai som to serve additional one-month per year in direct royal service. Taxpayer servants, Phrai suai (); Those Phrai who resided in distant regions and whose journey to periodically serve was impractical can pay the tax called Suai () instead of physical service. The Suai were usually local commodities and valuables, which the royal court would collect and sell to the foreigners as a source of revenue. Slaves, That (); The That slaves were, by law, considered properties of their masters that can be traded, inherited and given to other people without That consent. In contrast to Phrai who were allowed freetime, That slaves were always in the service of the masters and usually lived in the same quarters. Both men and women can be slaves. The majority of the That rooted in the economic cause. Those commoners who faced financial problems could "sell" themselves to become slaves to earn money. Those who defaulted the debts would become slaves of their lenders. Parents and husbands could also sell their children or wives to become slaves. When a slave managed to repay the debts, the slave would be freed (Thai , to be free). Only two types of slaves that were lifelong and irredeemable. They were That Nai Ruean Bia () who were born from slave parents in their services, and That Chaleoi () or the war captive slaves. If a slave woman became a wife of the master or his son, she would be freed. If a slave was captured by the enemy troops and managed to break free and return, the slave would be freed. Outside the social pyramid were the Buddhist monks, who were revered and respected by the Siamese of all classes including the king. The Buddhist monks were exempted from corvée and any forms of taxation as, according to the vinaya, monks could not produce or earn wealth on his own. Religion Maintenance of orthodox Theravadin Sangha