The United National Liberation Front (UNLF), the oldest Meitei insurgent group in the Manipur was formed under the leadership of Areibam Somorendro Singh on November 24, 1964 to achieve independence and a socialist society. A pan-Manipuri Youth League was formed in December 1968, which functioned as an overground body for UNLF. Later, differences within the outfit surfaced over the issue of strategies to be adopted.

While Somorendro sought to spread ideological consciousness before launching an armed struggle, the more radical leader Oinam Sudhir Kumar established the Revolutionary Government of Manipur (RGM). Somorendro was killed by unidentified militants in Imphal on June 10, 2001. In the seventies and eighties, the UNLF concentrated mainly on mobilisation and recruitment. In 1990, it decided to launch an armed struggle for the 'liberation' of Manipur from India. In the same year, it formed an armed wing called Manipur People’s Army (MPA).

Rajkumar Meghen alias Sana Yaima is the current chairman of UNLF. Other important leaders include general secretary T Sanachou; secretary of defence A Wangpa; secretary of organisation M Nongyai; and secretary of publicity N Thabal. The women's wing chief is Nganbi Devi; deputy women's wing chief is Banti Devi.

Soon after its formation, UNLF leaders established a political relationship with the authority of the then East Pakistan, and underwent military training in that country in 1969. They also supported the Pakistani army during the 1971 Bangladesh liberation war. Later, the group also developed a relationship with China even while continuing its relations with Pakistan.