Assam Chief Minister Himanta Biswa Sarma, in a social media post late on Friday, said India "formally submitted Rangpur-Sivasagar Ensemblethe capital of the Ahom dynasty that ruled the Brahmaputra Valley unbroken for six centuries - for UNESCO World Heritage status under criteria (iii) & (iv)".

According to criterion (iii), the site has to bear a unique or at least exceptional testimony to a cultural tradition or to a civilisation which is living or which has disappeared, while criterion (iv) suggests that it has to be an outstanding example of a type of building, architectural or technological ensemble or landscape which illustrates a significant stage in human history.

Sarma mentioned that the complex nominated by India houses Assam's "finest Ahom temples, palaces, water tanks and engineering marvels - including Rang Ghar, Asia's oldest surviving amphitheatre".

" This builds on the landmark 2024 UNESCO recognition of the Charaideo Moidamstogether, the two sites complete the Ahom story: where the dynasty rests, and where it ruled," he added, thanking Prime Minister Narendra Modi for "this unprecedented push to give Assam's heritage the global recognition it deserves".

The nomination comes after the UNESCO recognition for Charaideo Moidams, another heritage site of the Ahom era.

The Ahom dynasty was founded by Swargadeo Chaolung Sukapha in 1228, with its rule coming to an end in 1826.

Beyond its historical significance, the nomination comes against the backdrop of growing concerns over the vulnerability of Assam's heritage to extreme weather events, particularly the devastating floods that hit Upper Assam in July. The July 19 floods affected at least 12 archaeological sites across Sivasagar and Charaideo districts, with officials reporting damage from silt deposition, algae growth and deterioration of lime plaster at several historic monuments.