United Liberation Front of Asom (ULFA) was formed by Paresh Barua along with some associates including Rajiv Raj Konwar alias Arabinda Rajkhowa, Golap Baruah alias Anup Chetia, Samiran Gogoi alias Pradip Gogoi and Bhadreshwar Gohain on April 7, 1979, at the historic Rang Ghar in Sibsagar to establish a "sovereign socialist Assam" through an armed struggle. ULFA remained dormant in its initial years. In 1986, it first established contacts with the then unified National Socialist Council of Nagaland (NSCN) and the Kachin Independence Army (KIA) of Myammar for training and arms. Subsequently, links were established with Pakistan's Inter Services Intelligence (ISI) and Afghan mujahideen. Reports indicate that about 200 ULFA activists received training in Pakistan and Afghanistan. Seized documents and interrogation of some arrested activists revealed that the Defense Forces Intelligence (DFI) of Bangladesh had trained ULFA cadres in Sylhet district. Moreover, ULFA set up a number of training camps and sanctuaries in Samdrup Jongkhar Valley of Bhutan. Close nexus between ULFA and Liberation Tigers of Tamil Eelam (LTTE) had also been reported with LTTE training some ULFA cadres in handling explosives.

Since the late eighties, ULFA had been involved in a number of killings and abductions of government officials, security forces personnel, industrialists, businessmen and local politicians. It also carried out large scale extortion drives and looted banks and treasuries to finance purchase of sophisticated weapons and communication equipment. Like the Meitei and Naga insurgent groups, ULFA launched a series of social welfare and reform programmes in rural areas, helping people build roads and flood embankments through self-help. The outfit also fought social evils such as liquor, rape, corruption and rhino poaching.

As part of its social face the ULFA had also set up community farms in places such as Goalpara, Lakhimpur and Dhemaji. ULFA militants had infiltrated the State police and bureaucracy in Assam, and were running a parallel government in many parts of the State. The Home Minister in the first Asom Gana Parishad (AGP) ministry, Bhrigu Kumar Phukan was accused of giving clandestine support to ULFA. In 1990, the AGP government lost control of the law and order situation in the State with widespread violence being perpetrated by the ULFA. The AGP government was dismissed and the State brought under President's rule on November 28, 1990. ULFA was banned under the Unlawful Activities (Prevention) Act, 1967 and the army launched a massive counter-insurgency operation code-named Operation Bajrang which lasted until April 1991.

Although the top leadership escaped the army dragnet, 209 hardcore activists were apprehended. A large quantity of arms and Rs. 48 million in cash was recovered. On December 4, 1990, the army discovered a mass grave with 15 bodies in ULFA's Lakhipathar camp near Digboi, Tinsukia district. During operations, the army also recovered several incriminating documents which revealed ULFA's close links with other terrorist groups operating in Northeast. Operation Bajrang restored a semblance of order in Assam and elections were held in June 1991 to the State Legislature and a Congress government headed by Hiteshwar Saikia assumed office.

However, ULFA resumed its terrorist activities immediately, abducting 14 officials of the Indian Oil Corporation and the State Additional Secretary, A.S. Srivastava. In view of a fast deterioration in the law and order situation, the army launched Operation Rhino on September 15, 1991 and continued until January 14, 1992. During this operation, 2578 hardcore ULFA militants were nabbed with a large quantity of arms and Rs. 780,000 in cash. The army also destroyed 15 ULFA camps and collected several incriminating documents. In January 1992, the State government called off army operations and declared an amnesty for all militants who were willing to surrender. By March 1992, about 4000 activists led by Sunil Nath, publicity chief of ULFA, surrendered to the authorities.

Counter-insurgency operations were resumed and in April-May 1995, the Indian and the Myanmarese armed forces jointly launched Operation Golden Bird along the Indo-Myanmar border in which about 50 militants were killed and huge quantity of arms and ammunition were recovered. On January 20, 1997, a unified command structure was established to coordinate the functioning of the various Indian security forces carrying out operations against the militants. These counter insurgency operations have considerably weakened the ULFA, driving its top leadership into exile.

The ULFA has established a strong base in Bangladesh running several camps in the country. ULFA's Bangladesh connection was exposed when its leader Anup Chetia was arrested by the Bangladeshi authorities on December 21, 1997 Apart from running training camps, ULFA launched several income generating projects in Bangladesh. It set up a number of firms in Dhaka covering media consultancies and soft drink manufacturing. Besides it owns three hotels, a private clinic and two motor driving schools in Dhaka. ULFA also runs a profitable narcotics business in Myanmar and Thailand. The profit earned from these projects have been used to fund the lavish life style of the ULFA leaders.