The two major studies of early Ayutthaya over the past generation -- Charnvit Kasetsiri's The rise of Ayudhya (1976) and Srisakara Vallibhotama's Sayam prathet (1991) -- also stressed the territorial frame. In Charnvit's original version (adjusted later, as will be discussed below) the rise of the Ayutthayan kingdom was a process of territorial agglomeration carried forward by the competing ambitions of local lords. Three local muang (Ayutthaya, Lopburi and Suphanburi) were forged into a federation under one ruling family. This confederation then developed a ring of outlying cities and finally absorbed Sukhothai and neutralised Angkor, emerging as the dominant power in the Chaophraya basin. (2) In Srisakara's study, the motor of history is a process of increasing anthropological complexity. Trade networks become more complex and populations become more mixed in both economic function and ethnic background, while political forms evolve to manage this complexity. By this process, society moves from household to village (ban) to muang and finally to prathet (state, country) and anachak (kingdom). The emergence of Ayutthaya is a climactic event in this process, the transition to a new anthropological stage, the foundation of ratcha-anachak Sayam -- the baseline of modern history. (3) In their different ways, both Charnvit and Srisakara pictured the emergence of Ayutthaya as a process of territorial aggrandisement, and portrayed Ayutthaya from its inception as a land-based state inheriting elements from the hinterland Tai muang and from Angkor.
Since then, Ayutthaya's role as a commercial power has received increasing attention. Atsushi Kobata and Mitsuyu Matsuda made available translations from the Ryukyu archives on early trade between Japan and Ayutthaya, and Iwao Seiichi and Yoneo Ishii published analyses of this trade