In 1759 A.D., large forces under the command of the Burmese King Alongpaya moved against Ayutthaya. Prince Uthoomporn took back command of the Siamese forces for the defence of the city. During the battle King Alongpaya was killed and the Burmese army retreated back to burma.
Once again in 1764, during the reign of the Burmese King Hsinbyushin, the Burmese moved to great armies towards Ayutthaya. The first moved in from the North and captured chiang mai. The other moved in from the West. When the two armies combined they moved against the city of Ayutthaya and totally destroyed it. During the battle they burned palaces, noblemen's mansions, temples, warehouses and thoudands of houses. Ayutthaya finally fell on 8th April 1767. This was the end of 417 years of Ayutthaya as capital of the Kingdom.