1238 – Taking advantage of the weakening of the Khmer empire, two local Thai princes, Khun Bang Klang and Khun Pa Muang, both of them actually officials of the Khmer occupation government in Sayam (later, and until the present, Sukhothai) start a rebellion against the Khmers. Khan Lampong, a Cambodian General, tries to subdue the Thais but is defeated.
Sukhothai thereby becomes a truly independent state. Khun Bang Klang is crowned King of Sukhothai under the title Sri Inthrathit. Khun Pa Muang is only given a major government post, far inferior to the reward of Khun Bang Klang. The reason for this is his marriage with a Khmer princess – a matter that casts doubt on his trustworthiness in the Thais’ eyes. The Principality or Kingdom of Sukhothai grows rapidly in the following years – as a result of military conquest as well as rather diplomatic annexations of other Thai principalities formerly ruled by Khmers. These diplomatic annexations become possible because according to today’s knowledge, Sukhothai is an attractive state to join. It is much more liberal than most states of the time, knowing no slavery nor excessive taxation by the monarchy. Being a new kingdom, the rulers have not progressed on the typical path of becoming distant from their subjects. Kings are not considered god-kings as it had been under Khmer rule.
1254 – Kublai Khan, Mongolian ruler in central China conquers the Nanchao Kingdom, several hundred kilometers to the north in today’s southern China. Great waves of Thai migrants flood Sukhothai from Yunnan enhancing Sukhothai’s population and power base.
1262 – Prince Mengrai of Nanchao, after having escaped the wrath of Kublai Khan, establishes the Lannatai Kingdom with himself as king. To serve as his capital, he founds the town of Chiang Rai. In the following years, he integrates several neighboring Thai principalities into his kingdom. Although relations with Sukhothai are cordial for the first decades and in spite of the fact that many former Nanchao subjects become citizens of Sukhothai, the two kingdoms do not unite. Lannatai will later first become an ally of the Burmese against the Thai Kingdom of Ayutthaya (Siam) and then be a Burmese vassal or integrated into Burma for several centuries. It is noticeable in present-day Thailand that, except in Chiang Mai and the utmost north of today’s Thailand, Thais have much less sentiments about the kingdom of Lannatai than about Sukhothai, even though the independent history of Lannatai is considerably longer than that of Sukhothai (a mere 140 years).
1279 – Ramkhamhaeng, the third of three sons of Sri Inthrathit becomes king of Sukhothai. He is however preceded on the throne by his elder brother Ban Muang (not to be confused with Prince Pa Muang who had joined Sri Inthrathit in overthrowing the Khmer rule). But there are no records on when Sri Inthrathit died or for how long Ban Muang ruled. As there are no records it was most probably an exceptionally peaceful time. This changes when Ramkhamhaeng ascends to the throne. In the following years Ramkhamhaeng’s armies conquer an area encompassing most of what is now Thailand plus the eastern part of what is today Burma plus almost the whole of the Malayan Peninsula. Ethnically speaking, he ruled not only over Thais but also over Burmese, Mons and Shans in the west, Malays in the south and Khmers and Laotians (ethnically closely related to the Thais) in the east. As the relations between King Mengrai of Lannatai and King Ramkhamhaeng of Sukhothai have remained cordial, Ramkhamhaeng does not touch his northern neighbor. Impressing as they may be, Ramkhamhaeng’s military exploits are by far not his only achievement. He also creates the Thai alphabet that is basically still in use, codifies the law and conducts a reform of Buddhism practiced in his realm by establishing stricter rules for the behavior of monks. The Thai alphabet invented by him draws on Sanskrit and Pali (both languages of Indian origin) as well as the written languages of the Burmese and the Khmers, both of which are also Sanskrit and Pali based. But not only are the letters of neighboring languages used to provide for a written Thai language. Terms from Pali, Sanskrit and the immediate neighboring languages are also integrated into Thai (which otherwise is quite different from Burmese and the Khmer language). The development of the Thai language in southeast Asia, in spite of it’s origin in China, explains why a large number of Royal titles or religious designations are quite similar to those of the Khmer or Burmese (the Thais adopted Buddhism only in southeast Asia, not during their history in what is now south China where Buddhism arrived only at a time when the Thai majority had already migrated to southeast Asia). 1282 – How Chow Chi, a Chinese Mandarin comes to Sukhothai and negotiates a treaty of amity between China and Sukhothai.
1283 – King Mengrai of Lannatai conquers the Mon Kingdom of Haripungaya (present-day Lamphun), making it a long lasting part of his realm. Later kingdoms of the Mons will all be located at the western side of the mountain range that today separates the territories of Burma and Thailand.
1300 – Death of Ramkhamhaeng; the throne is ascended by his son, Loetai. Sukhothai begins its decline. In the following years, most of the non-Thai principalities ruled by King Ramkhamhaeng and many of the Thai principalities as well become rather independent from Sukhothai.
1338 – The major Thai principality of Phayao east of Chiang Mai is annexed to the Lannatai Kingdom.
1330-1350 – The principality of Utong (near today’s town of Suphanburi, close to Ayutthaya, becomes a regional power, largely due to the military skills of its leading general. A personal name of this general is not known. (It must be noted here that in Thai or Siamese tradition, personal names have much less bearing than in the western culture. Typically, a man changed his name when he assumed additional power, either by being promoted or by usurping it. Many of the names under which important Thai or Siamese personalities are known in history are anyhow rather titles than names. One important example of later times is the designations Chao Phaya. Chao Phaya, aside from being the name of the main Thai river, is a Thai title, designating the highest government officials; typically the leading general of a principality was named Chao Phaya – as for example several hundred years later Chao Phaya Chakri, the founder of the current Thai dynasty who had first been the leading general of King Taksin of Thonburi). The leading general of Utong (who didn’t bear the title Chao Phaya during his life-time but would later be designated as such) gains for his principality several adjourning areas which have so far been ruled by the king of Sukhothai. He is the initiator of the Ayutthaya period of Thai history.
1347 – Prince Lutai (Tammaraja I) , a son of King Loetai, becomes King of Sukhothai. It is not known how long Sukhothai was ruled by King Loetai. The accepted theory is that after King Loetai died, there was heavy competition for the throne; most probably a king with the name Nguanamthom ruled for a period of time between the reigns of Loetai and Lutai Tammaraja I. King Lutai concentrates rather on religious than political matters, a fact further contributing to the loss of political power of Sukhothai. Tammaraja, a name he acquires posthumously, is a religious rather than political title.
1370 – King Lutai dies and is succeeded by his son Prince Sai who becomes King Tammaraja II.
1371 – King Boromaraja I of Ayutthaya invades Sukhothai territory, capturing several towns.
1375 – Phitsanulok, the substitute capital of Sukhothai, is taken by Boromaraja’s forces and prisoners are turned into slaves.
1378 – King Tammaraja II is forced to become a vassal of the King of Ayutthaya. This marks the end of the independent Thai Kingdom of Sukhothai after 140 years of existence.
1350 – The leading general of Utong, upon the death of the kingdom’s ruler, becomes King of Utong himself and assumes the title Rama Tibodi I. One of his first decisions is to transfer his capital some 50 kilometers (31mi) to the east, to the thriving trade town of Ayutthaya. (The similarity to the beginning of the Bangkok period in Thai history is striking; 432 years later, it is again the leading general of a preceding king who becomes king; at both instances, one of their first tasks is to transfer their capitals; contrary to what is often read in English language guide books, both towns, Ayutthaya and Bangkok, are not “founded” by the two kings but were already well established settlements, though with no political functions.)