Ayutthaya-Lanna War

Yuttittira – a Sukhothai royalty and Trailokanat’s relative - was a close childhood friend of Trailokanat. Trailokanat himself promised him the title of Uparaja. However, after Trailokanat’s reforms, Yuttittira ended up with the title of the Governor of Pichit. Yuttittira also claimed to be the rightful king of Sukhothai.

The Lanna kingdom under Tilokaraj was so powerful that he led armies down south to subjugate Ayutthaya. In 1456, Yuttittira sought Tilokaraj’s support and led Lanna armies to capture Sukhothai and proceeded further towards Ayutthaya. Trailokanat, however, led Ayutthayan armies to defeat the Lanna armies.

In 1461, Tilokarat and Yuttittira led the Lanna armies to invade Ayutthaya but without achieving fruitful results and retreated. Trailokanat then took this opportunity to retake Sukhothai. Trailokanat, upon seeing the seriousness of the wars, crowned himself as the king of Pitsanulok in 1463 – thus moving his base from Ayutthaya to Pitsanulok – to be able to cope with Lanna wars. Trailokanat, accompanied by more than 2,000 followers, was the first Siamese king to be ordained as a monk. The ordination took place at Wat Chula Manee in 1461.

In 1463, the Lanna invaded again. Trailokanat sent his son, Prince Indraracha, to crush the invading armies. Indraracha defeated Yuttittira but was in turn killed during battles against Nagara – Tilokaraj’s uncle.

Lanna then, however, was plunged by her own internal princely conflicts. In 1474, Trailokanat finally expelled the Lanna out of his kingdom. Next year, Tilokaraj sought peace settlements.