The third historical assumption leading to Ayudhy being understood as a strong centralized state derives from a misapprehension concerning the significance of the numerous military operations of the early Ayudhya kings in neighboring territories. The best known case is the invasion of Angkor in A.D. 1431 by Boromracha ll (424-48), who was the father Trilok 51 Even though the rulers of Ayudhya from time to tim exerted their military power in all directions (Sukhothai and Chiengmai in the north, Cambodia in the east, Tavoy in th west and Malacca in the south) they could not, with the tion of Sukhothai, incorporate these remote principalities in the Ayudhya political and administrative domain. Most of these areas maintained their independence and only some were tributary states. However, at any time when Ayudhya rulers were weak or the kingdom was captured and reduced to a lower rank by a victorious rival, as in the reig lor Chakkraphatl (1548-69), and Phra Mahathamracha (1569-90), the former tributary kings usually took the opportunity to declare their complete and sometimes waged war against Ayudhya sz Thus, theinva sions by early Ayudhya kings of close and distant regions alik are not a convincing standard for evaluating the centralized of Ayudhya. As happened in Burma, shortly after th death of strong and warlike rulers the vast but loosely organ kingdom started to fall apart. Van Vliet, in The Short Hi tory of the Kings of Siam written early in 1640, describes the litical after the death of King Naresuvara (1 powerful and king of Ayudhya: "Many countries and cities which the king conquered and seized remained in subjection till the end of his life, such as Cambodia, Champa various in Muang Hang, Lan Chang, Chiengmai, the cit cities Lakhon, Lao, and Kreng. but because no occu pation or military force was left in these places (as in the Euro- pean manner, these places broke away from the Siamese king dom after His Majesty's death and were never again brough back to obedience, except for the cities Lakhon and Lao, as will be seen in what follows. "53