In 1622 and 1623 there were various skirmishes between Siam and Cambodia. Both kingdoms were involved in international trade, and to a great extent their fortunes depended upon it. There war with Cambodia and, perhaps, the great fire in the Nihonmachi of 1622, prevented Song Tham from keeping his promise to send an embassy to Japan in 1622, as Okya Si Thammarat notified Sakai Tadao by letter. However, the Siamese were ready to send their entourage to Edo again in 1623.
The Siamese arrived in Nagasaki in August and from there they proceeded to Kyoto, where they met with the retired Hidetada, and the new shogun, his son Iemitsu. The latter received the envoys in his castle at Fushimi. Besides the usual compliments (the Siamese royal letter described Siam and Japan as “one country”) and more comments about the wisdom of Buddhism, Song Tham’s letter expressed some concern regarding the situation at the border with Cambodia.
In the following three years, from 1624 to 1626, the shogunate issued only one permit to travel to Cambodia, in 1625. This was not part of a general reduction of the ships sent to Southeast Asia; in fact, during the same period, six shuinsen went to the Siamese capital. The alliance between Ayutthaya and Edo was at this stage stronger than ever. The symbiosis between Siam and Japan is even more interesting, considering how, by choice or fate, Ayutthaya and Edo also shared similar policies toward the Europeans.
Resources: “Samurai of Ayutthaya – The Historical Landscape of
Early 17th Century Japan and Siam: Yamada Nagamasa
and the Way to Ayutthaya” by Cesare Polenghi (p. 45-46)
