Future royal succession is a major factor influencing contemporary politics in Thailand.
However, elite politics has played a major role in the history of both countries for hundreds of years and there are strong overtones of the past in present-day events, so it perhaps behooves the student of contemporary events to look back at past events.
This decline happened over an almost 100 year period from 1648 to 1752 (from the reign of the Burmese king Pindale to the final Toungoo kings Taninganway and Mahadhammaraza Dipadi) (see here).
Victor Lieberman's magisterial "Burmese Administrative Cycles: Anarchy and Conquest, c. 1580–1760" based on his PhD dissertation at the SOAS, analyses the history of this decline and the role of elite politics in great depth, perhaps deeper than any other work on Burmese history (see organization of the book here).
ELITE POLITICS
Burmese society of the Toungoo period was one gigantic patron client network or hierarchy.
Everyone was basically in service to someone else.
The most fundamental distinction was between royal servicemen (ahmu-dan) serving the king directly (ahmu-dan), and free servicemen (athi) whose service and taxation burdens were much less burdensome,
Royal servicemen formed the core of the Burmese armed forces and also constituted an important tax base for the central royal government.
Because of the greater burdens many royal servicemen attempted to exit their legal status by whatever means possible entering into the service of princes or other elite.
Becoming a slave when debts accumulated to the point of insolvency was also a means of escaping from royal service.
The flow of manpower from royal service reached almost epidemic proportions during the 100 year period mentioned above (1648-1752) and in the end was a major factor in the collapse of the Toungoo dynasty.
BURMESE ADMINISTRATIVE CYCLES AUDIO DOWNLOAD
Victor Lieberman's masterwork, unfortunately, is rather difficult to find in Burma, so I provide here a recording of a key section that I recorded for my personal study (see zip file of mp3 files here).
Hopefully, Wikipedia will be updated one day soon to incorporate his wonderful research work. I personally hope to build a model of elite role in the politics of the pre-modern Burmese state using agent-based modeling and analytical sociology and the models of Peter Turchin based on the so-called Secular cycles (see here & here). Such models could facilitate comparison across time periods within Burmese history and across polities or proto-states in Southeast Asian history.
REFERENCES
Lieberman, Victor B. (1984) Burmese Administrative Cycles: Anarchy and Conquest, c. 1580–1760, Princeton University Press.