Prasat Thong gave another proof of his capacity to deal with things not going his way when, upon receiving news of Yamada Nagamasa’s success, he sent presents and “young women” to congratulate him. Of course, for him it would have been much better if Nagamasa had died in the battle of Ligor. However, the Japanese was a problem the newly crowned king of Siam was determined to solve, since the last thing he needed was Nagamasa coming back to Ayutthaya. Together with the presents to Ligor went the report that the former Kalahom was now king, a piece of news that surely didn’t please Nagamasa. However, his thoughts about this new matter had to be postponed, as Ligor was ready to welcome a new queen: Nagamasa’s favourite of the ladies sent by Prasat Thong.
Historical and literary sources make no mention of the woman who allegedly gave a son, Oin, to Nagamasa. The only woman associated with Nagamasa is this Siamese companion, depicted in some versions as a treacherous agent sent by Prasat Thong. In some fictional account of Nagamasa’s life, he falls in love with a Siamese princess in Ayutthaya.
Version 1 (from secondary sources): The last chapter of Nagamasa’s life, probably taking place around April or May of 1630, is described in dramatic terms by van Vliet. The king of Ligor (ie Nagamasa) at the time was still suffering from a wound he had received in a battle the Japanese had lost in Patani, a kingdom he and his men repeatedly failed to annex to their territory of Ligor. Pretending to show compassion, Prasat Thong had sent from Ayutthaya some balm to be applied to soothe the pain. It was the brother of the former king of Ligor, Opra Narit, who took care of it.
As the party celebrating Nagamasa and his newly-wed queen was reaching its climax, tragedy struck. Nagamasa suddenly fell sick, and soon enough it was clear he was going to die. In fact, Opra Narit had not applied a medicament, but poison, of course sent from Ayutthaya by Prasat Thong. The poison quickly took effect and just a few hours later, Nagamasa died.
Version 2: The above version is not historically sound. In Tsuko Ichiran, a primary source written by a Japanese who resided in Ayutthaya’s Nihonmachi, the main culprit of Nagamasa’s death is not Prasat Thong, but his lover, a Siamese queen. Allegedly, she eliminated Song Tham, her son (possibly Cetthathirat) and finally Nagamasa by having them poisoned one after the other. In this version, Nagamasa never goes to Ligor. It is his son Oin who was given a chance by the queen to conquer the southern kingdom, as a way to soothe Nagamasa’s anger after the poisoning of the legitimate royal heir. In the meantime, Nagamasa himself was killed by a royal aide called Chantoho (who has a similar role to van Vliet’s Opra Narit, and could be the same historical character).
Moreover, in this Japanese version of the events, poison was put in Nagamasa’s food, and it took a few months for Nagamasa to die. His demise is also set three years off from other versions, being (wrongly) dated 1633. The Siamese queen rewarded Chantoho for killing Nagamasa by offering him the province of Ligor, which she had previously given to Oin. However, Nagamasa’s son took his revenge by quickly gathering a small army and killing Chantoho. (This version is also improbable as it loses most of its historical credibility by featuring a queen whose existence finds no substantiation in other sources!)
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. 57-59)
