The Hynniewtrep National Liberation Council (HNLC) is a product of a 1992 split in the Hynniewtrep Achik Liberation Council (HALC), the first tribal outfit in Meghalaya. The HALC split due to inter- tribal antagonisms leading to the formation of the HNLC and Achik Matgrik Liberation Army (AMLA). In the erstwhile HALC, the Hynniewtreps (Khasis, who trace their origin to seven celestial families) represented the Khasi and Jaintia tribes and the Achiks represented the Garos, in a common fight against the Dkhars, a genetic term for outsiders.

HNLC, also known as the 'Sawdak' is led by its Chairman Julius K. Dorphang, General Secretary Cheristerfield Thangkhiew and Commander-in-Chief Bobby Marwein. M Diengdoh is the outfit’s publicity secretary. The outfit largely has the characteristics of an urban terrorist group and is active in the East and West districts of Meghalaya, particularly in and around the capital, Shillong. Its headquarters are reportedly located in Mawlai and Jailaw. The group maintains links with other terrorist groups in India's Northeastern region, particularly the National Socialist Council of Nagaland—Isak-Muivah (NSCN-IM).

The purported aims of the HNLC are typical of an outfit claiming to fight for the ethnic rights of a backward group. One of its claims is that it aims to transform Meghalaya as a province exclusively for the Khasi tribe, which, it adds, has long been dominated by the Garo tribe. A second aim is to fight against the presence of 'outsiders' as it feels that Khasi youth are deprived of the fruits of development in the state. The outfit has exploited perceived insecurities among Khasi youth to increase its base in the State. These insecurities, particularly a sense isolation and alienation, are a consequence of the perception of being 'exploited' by outsiders.

In the year 1995, the HNLC launched 'Operation Kyllano' to eliminate people opposing the activities of the outfit. Subversive activities of HNLC intensified after the United Democratic Party led coalition of myriad regional parties formed the government in February 1998 with B.B. Lyngdoh as the Chief Minister. HNLC’s rise coincided with the political turmoil in the state more so after E.K. Mawlong took over as the Chief Minister in April 2000.

HNLC terrorists were responsible for the loot of Rs. 900,000 from a bank on April 12, 2000. The outfit, along with another prominent terrorist outfit, Achik National Volunteer Council (ANVC), declared a 36-hour bandh in a bid to disrupt the Independence Day celebrations on August 14, 2000. On August 15, HNLC terrorists struck engaging the security forces in a four-hour gun battle simultaneously at seven key points of the State capital, including the residence of the Governor. One security force personnel was killed in one of these incidents. In the year 2000, the HNLC terrorists killed three civilians and three security force personnel. In all six HNLC cadres were also killed in various encounters.

On January 5, 2001, five civilians were killed and four others injured in an attack by HNLC terrorists on a business establishment in Shillong. Four days later, on January 9, two security guards of a nationalised bank were killed in an attack by HNLC terrorists in Mawsynram village . On January 19, 2001 HNLC terrorists attacked a police outpost in Shillong killing two police personnel.Two more police personnel were killed in a March 28, 2001 encounter with HNLC terrorists near Jaiaw Longsuing, in Shillong. The outfit, in a statement released on February 19, 2001 opposed the Census operations in the State and threatened to eliminate the enumerators participating in the process.

Ministry of Home Affairs (MHA) sources indicated that the HNLC raises large sums of money through extortion and looting. The prime targets for this are non-tribal businessmen in the State. These illegitimate funds are used to procure sophisticated weapons. It also promotes the circulation of fake currency in the state, which was started at the behest of Pakistan's Inter Services Intelligence (ISI).

The two prominent terrorist outfits in the State, HNLC and ANVC have consistently adopted a recalcitrant attitude towards any offers for a negotiated solution to their perceived issues. In June, 2000 the Meghalaya government had issued an invitation to both the HNLC and ANVC for a dialogue, an offer which was rejected by the HNLC. On January 17, 2001, the then Joint Secretary in charge of Northeast in the MHA, G K Pillai, during the visit to the State, expressed the Union Government's willingness to enter into a dialogue process with the HNLC leadership. However, the outfit has failed to respond to the offer. The Church leaders in the State have also been involved in initiating a peace process with the HNLC. In the month of January 2001, the Khasi Jaintia Church Leaders' Forum sent letters to the HNLC leaders to participate in a dialogue process. A rehabilitation package for surrendered terrorists, announced by the state government has also been rejected by HNLC.