The Zenith of the Ahom power was reached in the reign of RudraSinha or Sukhrungpha (1696-1714). He founded new capital at Rangpur presently known as Sivasagar. During his reign subjugation of Cachar and Jaintia was completed in 1700 A.D., and Nagas were brought under the control of Ahom kingdom.
In 1745, Sunenphaa or Pramatta Singh, the second son of Rudra Singh ascended the throne. He was the first king who carried a Census in the country.
Swargadeo or Rajeswar Singha , the fourth son of Rudra Singha, became the king of the Ahom kingdom after the death of his brother King Pramatta Singha. During his reign of power, the Raja of Manipur applied for aid. RajeswarSingha sent one expedition and it ended in failure while crossing Patkai. The second expedition was despatched in 1762 but that too was a less successful. However this helped good alliance between the Ahom and Manipuris, which led to religious and cultural contacts between the two countries.