Nai. The two top ministers, Samuha Nayok and Samuha Kalahom, were always ranked Chaophraya in the Bangkok period. The Four Ministers of Chatusadom were initially ranked Phraya in the reign of King Rama I, with some exceptions. They were later elevated to Chaophraya in subsequent reigns. Sakdina is the theoretical amount of land and numerical rank accorded to an official for his position in bureaucracy, which determined the amount of production received and the severity of punishment for crime. The Sakdina of each every single government position was described in the Three Seals Law. For example, the Sakdina of Samuha Nayok, Samuha Kalahom and the Four Ministers of Chatusadom were 10,000 rai each. Regional government Cities and towns in 'Siam proper', which correspond roughly to modern Central and Southern Thailand, were organized into the 'Hierarchy of Cities', in which small towns were under the jurisdiction of larger cities. There were four levels of cities, in descending order; the Mueang Ek (), Mueang Tho (), Mueang Tri () and Mueang Chattawa (). Mueang Ek was the highest level of city representing regional centre. The Mueang Eks in the Rattanakosin period were Nakhon Si Thammarat, which was the centre of Southern Siam, and Nakhon Ratchasima, which was the centre of the northeast. Phitsanulok, which had been the centre of Northern Siam, used to be Mueang Ek in the Ayutthaya period. However, Phitsanulok was largely depopulated in the early Rattanakosin due to the wars in the Thonburi period and its role as an outpost against northern Burmese invasions diminished in favor of Lanna kingdom. The cities and towns in Northern Siam were under jurisdiction of Samuha Nayok and Southern Siam under Samuha Kalahom. The governors of cities were ranked according to the level and importance of their cities. The governors of Mueang Eks were usually ranked Chaophraya. The local bureaucracy in each city was headed by the governor. Below the governor was the vice-governor called either Palat () or Tukkarat (), Below the vice-governor was the deputy vice-governor called Yokkrabat (). The governorship of large cities were usually passed down through generations of the same family due to that family's important role and connections in the area. The tributary kingdoms were called Prathetsarat (), each of which were political entities in its own rights and bound to Siam through the Southeast Asian political ideology of mandala system. Native culture and traditions were largely