Following the arrest of Sao Shwe Thaik of Yawnghwe in the Burmese coup d'état in March 1962 by the Revolutionary Council headed by General Ne Win, his wife, Sao Nang Hearn Kham (Mahadevi of Yawnghwe) fled with her family to Thailand in April 1962. Sao Shwe Thaik died in prison in November the same year and while in exile his wife participated in the independence struggle of the Shan State. In 1964, Sao Nang Hearn Kham became the leader of SSIA and tried to unify the four rebel factions. However, she could not make Noom Suk Harn and TNA agree for unification, therefore, SNUF merged with SSIA and formed Shan State Army (SSA). The formation took place at the headquarters of SSIA in the mountains near the Thai border. It aimed to expand its forces to a statewide organization by incorporating other rebel groups.