The party was founded in 1972 as Anna Dravida Munnetra Kazhagam (ADMK) by M. G. Ramachandran, a veteran Tamil film star and popular politician.
It was set up as a breakaway faction of the Dravida Munnetra Kazhagam (DMK) led by M. Karunanidhi, then Chief Minister of Tamil Nadu, owing to differences between the two.
Later, MGR prefixed the All India (AI) tag to the party's name.
Since its inception, the relationship between the AIADMK and DMK has been marked by mutual contempt.
MGR used his fan network to build the party cadre with claims his party recruited more than a million members in the first two months.
C. N. Annadurai's ideologue and movie mogul R. M. Veerppan was the key architect in unifying the MGR fan clubs and further consolidating the party structure in the 70s.
Other key leaders such as Nanjil K. Manoharan and S. D. Somasundaram played major roles in consolidation.
The party's first victories were the Dindigul parliamentary by-election in 1973 and the Coimbatore assembly by-election a year later.
On 2 April 1973, AIADMK emerged as the third largest political party in Tamil Nadu, represented by 11 MLAs in the assembly.
By 31 January 1976, AIADMK emerged as the second largest political party in Tamil Nadu with 16 MLAs in the assembly.
AIADMK grew close to the Congress Party by supporting the National Emergency between 1975 and 1977.

The DMK-led government was dismissed by a Central promulgation on corruption charges in 1976.
The AIADMK swept to power in 1977, defeating the DMK in the assembly elections.
MGR was sworn in as the 7th Chief Minister of the state on 30 June 1977.
MGR remained in power until his death on 24 December 1987, winning consecutive assembly elections held in 1977, 1980 and 1984.

In 1979, AIADMK became the first Dravidian and regional party to be part of the Union Cabinet, when two AIADMK MP's, Sathyavani Muthu and Aravinda Bala Pajanor, joined the short-lived Charan Singh Ministry which followed the Morarji Desai-led Janata Party government (1977–1979).

Relations between the Congress and the AIADMK slowly became strained.
In the mid-term parliamentary elections of January 1980, the Congress aligned with the DMK and the alliance won 37 out of the 39 state parliamentary seats.
 The AIADMK won just two seats.
After returning to power, the new prime minister, Indira Gandhi, dismissed a number of state governments belonging to the opposition parties, including the AIADMK government.

Elections to the state assembly were held in late May 1980 with the opposition DMK continuing the electoral alliance with the Congress.
In a massive reversal of fortunes following the Lok Sabha elections, the AIADMK won a comfortable majority in the state assembly with 129 of 234 seat.
 MGR was sworn in as chief minister for the second time on 9 June 1980.

In 1984, even with MGR's failing health and hospitalization, the party won the assembly elections in alliance with the Congress.
Many political historians consider MGR's persona and charisma at this point of time as "infallible", and a logical continuation of his on-screen "good lad" image, strengthened by his "mythical status" in the minds of the masses.
MGR continued to enjoy popular support in his third tenure until his death on 24 December 1987.
The party was founded in 1972 as Anna Dravida Munnetra Kazhagam (ADMK) by M. G. Ramachandran, a veteran Tamil film star and popular politician. It was set up as a breakaway faction of the Dravida Munnetra Kazhagam (DMK) led by M. Karunanidhi, then Chief Minister of Tamil Nadu, owing to differences between the two. Later, MGR prefixed the All India (AI) tag to the party's name. Since its inception, the relationship between the AIADMK and DMK has been marked by mutual contempt. MGR used his fan network to build the party cadre with claims his party recruited more than a million members in the first two months. C. N. Annadurai's ideologue and movie mogul R. M. Veerppan was the key architect in unifying the MGR fan clubs and further consolidating the party structure in the 70s. Other key leaders such as Nanjil K. Manoharan and S. D. Somasundaram played major roles in consolidation. The party's first victories were the Dindigul parliamentary by-election in 1973 and the Coimbatore assembly by-election a year later. On 2 April 1973, AIADMK emerged as the third largest political party in Tamil Nadu, represented by 11 MLAs in the assembly. By 31 January 1976, AIADMK emerged as the second largest political party in Tamil Nadu with 16 MLAs in the assembly. AIADMK grew close to the Congress Party by supporting the National Emergency between 1975 and 1977.
The DMK-led government was dismissed by a Central promulgation on corruption charges in 1976. The AIADMK swept to power in 1977, defeating the DMK in the assembly elections. MGR was sworn in as the 7th Chief Minister of the state on 30 June 1977. MGR remained in power until his death on 24 December 1987, winning consecutive assembly elections held in 1977, 1980 and 1984.
In 1979, AIADMK became the first Dravidian and regional party to be part of the Union Cabinet, when two AIADMK MP's, Sathyavani Muthu and Aravinda Bala Pajanor, joined the short-lived Charan Singh Ministry which followed the Morarji Desai-led Janata Party government (1977–1979).
Relations between the Congress and the AIADMK slowly became strained. In the mid-term parliamentary elections of January 1980, the Congress aligned with the DMK and the alliance won 37 out of the 39 state parliamentary seats.  The AIADMK won just two seats. After returning to power, the new prime minister, Indira Gandhi, dismissed a number of state governments belonging to the opposition parties, including the AIADMK government.
Elections to the state assembly were held in late May 1980 with the opposition DMK continuing the electoral alliance with the Congress. In a massive reversal of fortunes following the Lok Sabha elections, the AIADMK won a comfortable majority in the state assembly with 129 of 234 seat.  MGR was sworn in as chief minister for the second time on 9 June 1980.
In 1984, even with MGR's failing health and hospitalization, the party won the assembly elections in alliance with the Congress. Many political historians consider MGR's persona and charisma at this point of time as "infallible", and a logical continuation of his on-screen "good lad" image, strengthened by his "mythical status" in the minds of the masses. MGR continued to enjoy popular support in his third tenure until his death on 24 December 1987.
All India Anna Dravida Munnetra Kazhagam