By the late 13th century, the Siamese kings of Sukhothai had brought most of Malaya under their rule.

Portuguese chronicles noted that the king of Sukhothai had sent an expedition to Malacca at the southern tip of the Malay Peninsula in 1455.

After the Ayutthaya kingdom had emerged and expanded its influence from the Chao Phraya valley, Sukhothai was finally subdued.

Once King Bayinnong had control over Kampaenphet, Sukhothai and Sawankhalok, he led his forces to the northern kingdom of Phitisanulok.

However the office of Kalahom and the military of Siam had existed since the days of the Sukhothai Kingdom in the 13th Century.

Sukhothai had enjoyed a substantial autonomy until it was re-conquered around 1180 by the Mons of Lavo under Khomsabad Khlonlampong.

In 1451, Yuttitthira, a Sukhothai royalty who had conflicts with Trailokanat of Ayutthaya, gave himself to Tilokaraj.

Yuttitthira urged Trilokanat to invade Pitsanulok which he had claims on, igniting the Ayutthaya-Lanna War over the Upper Chao Phraya valley ( i. e. the Kingdom of Sukhothai ).

By 1180 the Sipsong Panna had regained their independence from the Khmers, however, and in 1238 an internal uprising in the Khmer outpost of Sukhothai expelled the Khmer overlords.

By 1180 the Sipsong Panna had regained their independence from the Khmers, however, and in 1238 an internal uprising in the Khmer outpost of Sukhothai expelled the Khmer overlords.

Prasat Thong had just usurped the throne from the ruling Sukhothai dynasty in 1629 and founded a dynasty of his own.

He also had the support of his brothers and the Okya Sukhothai, a powerful nobleman.

In the 14th century, the centre of Thai power passed from Sukhothai to the more southerly Ayutthaya, in territory which had formed part of the Khmer empire.

In 1280, Mangrai first made peace between King Ngam Mueang of Phayao and King Ram Khamhaeng of Sukhothai, who had seduced the former's queen.

There followed a period of confusion in the succession, with six kings ruling in eleven years, which could have been disastrous if the northern powers had not fallen upon their own troubles, and Sukhothai to the south had not also been weakened.

His father was a Sukhothai noble, who had defeated Vorawongsathirat in 1548 and put Maha Chakkrapat on the throne.

The slightly higher northern plains have been farmed for centuries and saw a major change from the 13th century onwards during the Sukhothai Kingdom in the 13th and 14th centuries and the Ayutthaya Kingdom that succeeded it when rice-growing intensified with the introduction of floating rice, a much faster-growing strain of rice from Bengal.

The old capital, now 12 km outside of New Sukhothai in Tambon Mueang Kao, is in ruins and has been designated as a UNESCO World Heritage historical park.

The inscription and its image of a Sukhothai utopia remains central to Thai nationalism, and the suggestion that it may have been faked in the 1800s caused Michael Wright, a British scholar, to be threatened with deportation under Thailand's lèse majesté laws.

Although Isan is not thought to have been a part of the Sukhothai kingdom due to the lack of clear evidence, the Khmer empire became weaker and retreated to its Cambodian heartlands, leaving Isan in the hands of fragmented muang () city-states or statelets.

It was also this time that the first relation with Yuan Dynasty was formulated and Sukhothai began sending trade missions to China.

However, one interesting note is that a Tai army was shown as a part of Lavo army, a century before the establishment of the Sukhothai kingdom.

Modern historians stated that the secession of Sukhothai from the Khmer empire began as early as 1180 during the reign of Po Khun Sri Naw Namthom who was the ruler of Sukhothai and the peripheral city of Sri Satchanalai ( now a part of Sukhothai Province as Amphoe ).

While part of the Sukhothai kingdom, it was called Mueang Phra Bang, the southern frontier city of Sukhothai.

On December 12, 1991, it was declared a World Heritage Site as part of the Historic Town of Sukhothai and Associated Historic Towns together with the associated historic parks in Kamphaeng Phet and Si Satchanalai.

Historically Narathiwat was the part of the semi-independent Malay Sultanate of Patani, paying tribute to the Thai kingdoms of Sukhothai and Siamese kingdom of Ayuthia.

In 1289 it sent another embassy to China, but soon became part of the Thai kingdom of Sukhothai and later Ayutthaya.

The town Phichit was established in 1058 by Phraya Kotabongthevaraja, and was first part of the Sukhothai kingdom, and later of Ayutthaya.

From 1287 to 1564, Dawei became part of the Sukhothai Kingdom and its successor Ayutthaya Kingdom ( Siam ).

Nakhon Si Thammarat Kingdom or ( or Kingdom of Ligor ) ( ) was one of the major constituent city states ( mueang ) of the Siamese kingdoms of Sukhothai and later Ayutthaya and controlled a big part of the Malay peninsula.

After the Pagan Empire's collapse in 1287, Myeik became part of successive Siamese kingdoms ( first Sukhothai, and later Ayutthaya ) from the late 13th century to the middle of 18th century ( except between 1564 and 1593 when the Burmese temporarily regained control ).

Southeast Asia c. 1300 CE, showing Khmer Empire in red, Lavo kingdom in light blue, Sukhothai Kingdom | Sukhothai empire in orange, Champa in yellow, Dai Viet in blue and Kingdom of Lanna in purple.

Claimed territories of Mangrai's Lan Na include modern northern Thailand provinces ( with exception of Phrae – which was under Sukhothai – and Phayao and Nan – the Kingdom of Payao ), Kengtung, Mong Nai, and Chiang Hung ( modern Jinghong in Yunnan ).

Sukhothai enjoyed a golden age under their third king, King Ramkhamhaeng, who was credited with creating the Khmer-derived Thai alphabet which is essentially the same as that in use today.

Sukhothai, which literally means " Dawn of Happiness " with an area of 6, 596 km < sup > 2 </ sup >., is about 427 km north of Bangkok and was founded in 1238.

Sukhothai also produced a large quantity of glazed ceramics in the Sawankhalok style, which were traded throughout south-east Asia.

Lampang Airport is currently served by Bangkok Airways, which operate daily flights to Bangkok via Sukhothai

The collapse of Srivijaya was filled by the growth of the Kingdom of Nakhon Sri Thammarat, which subsequently became a vassal of Sukhothai.

At the time of the Sukhothai kingdom, the Nakhon Si Thammarat kingdom was already listed as one of the kingdoms under control of the Thai, which it has remained during most of its history.

Sukhothai also produced a large quantity of glazed ceramics in the Sawankhalok style, which were traded throughout south-east Asia.

The populace of southern Thailand, which captured Sukhothai in approximately 1350, was in the 14th century still largely Mon, and the fusion of styles resulted in the more solid, corporeal, and squared-off U Thong image.

This temple contains the Buddha image Phra Sri Sakyamuni or " Sisakayamunee " which moved from Sukhothai province.

The city's configuration was also found at other contemporary cities such as Maingmaw and Beikthano in the Pyu realm and Danyawaddy and Wethali in Arakan as well as later cities such as Sukhothai, which emerged over a millennium later.