The period of Thai-Burma warfare (c. 1548-1599) really needs a good literature review.
I've been focusing so much on the more obscure and overlooked periods of history such as Mingyinyo (r. 1486-1531) and Rajadhirat (r. 1383-1421) that I've missed some important sourceslike the book above.
Pamaree Surakiat's recent working paper on Thai-Burmese warfare has an extensive review of the literature and she'll problem have an even more focused review for the period of Thai-Burmese warfare (c. 1548-1599) in her PhD dissertation when it comes out.
The book above, reviewed recently in the SOAS Bulletin of Burma Research, has an important source that is a master's thesis done in Burma:
"The first article is the abridged version of a Master Thesis on Thai-Burmese relations prior to the mid-16th century submitted to the University of Mandalay by the historian and archaeologist U San Nyein."[Comment: Rajadhirat Ayeidawpon records invasions in the Martaban-Tenasserim area by Kamphaengphet and Chiang Mai which I cannot find verified in Tai language sources from Chiang Mai and Ayutthaya, so I don't really know what to make of these references yet. The more peaceful religous exchanges between the Sangha of Chiang Mai and Martaban-Pegu should be verifiable from both the Burmese and Tai side though, so this is probably a better way to begin.]
"Until the reign of King Tabinshwehti (1531–1551) relations between Ayutthaya and the Burmese kingdoms were relatively peaceful, reflecting the common idea of regarding the other side as outside one’s own sphere of influence."
"U San Nyein convincingly demonstrates that between 1548 and 1569 the Burmese modified their military strategy and tactics after each attack on Ayutthaya, the Siamese capital which was well protected by its geographic location. While not denying the expansionist nature of the military campaigns of Tabinshweti and his successor Bayinnaung (r. 1551–1581), U San Nyein claims that they were motivated by self-defence as it was the Siamese who set in motion the military confrontation by occupying a Burmese township at the Gulf of Martaban (p. 68) which, however, was claimed by Ayutthaya as her own vassal müang.[Comment: Once some initial incidents trigger an escalaton, a cycle of tit-for-tat long distance warfare like during the Rajadhirat era (c. 1383-1421) determining who is to blame doesn't seem like the right question to ask. Wouldn't it be more useful to unravel the process of escalation. Some periods are peaceful. Some periods suffer from endemic warfare. What gets those periods of endemic warfare going and what stops them? Cross-cultural research using other histories outside the region would be useful here also. The Maori Musket Wars of the early 19th century driven by plentiful supplies of muskets are a good example. James Belich's Making Peoples: A History of the New Zealanders: From Polynesian Settlement to the End of the Nineteenth Century (1996) (at Chulalongkorn Library in Bangkok) gives a good overview.]