King U Thong (Ramathibodi I)

Founding monarch of the Ayutthaya Kingdom, which went on to rule Siam for more than 400 years.

Life

Chief of U Thong

There are various accounts of King U Thong's origins; one holds that he was the chief of the city of U Thong. Through marriage alliances and alliances he gained power in the lower Chao Phraya River basin.

Made Ayutthaya the capital

In 1351 he founded the city of Ayutthaya on an island in the Chao Phraya River and took the throne as Ramathibodi I. He promulgated laws, supported Theravada Buddhism and sent troops against the Khmer at Angkor, expanding his power.

Promulgated laws

He died in 1369. The Ayutthaya Kingdom he founded lasted until 1767 and was one of the most powerful states in Southeast Asia; Chinese historical records called it "Siam."

Legacy

The Ayutthaya Kingdom founded by King U Thong lasted more than 410 years, and the ancient city of Ayutthaya is today a World Heritage Site.

Did you know? In 1370, shortly after the founding of the Ming dynasty, Siam sent envoys bearing tribute, and the two countries had very frequent contact thereafter.

Key dates

• 1351Founded the city of Ayutthaya
• 1352Sent troops against Angkor (approx.)
• 1369Died