A look at the key players in the ruling party that is undergoing tectonic shift as it struggles to come to terms with the void created by Jayalalithaa's unexpected death on December 5 at an age of 68.
Overcoming an initial split in the party, she rose to become its undisputed leader and guided it after the death of Ramachandran in 1987. She was a five-time Chief Minister of the southern state.
Jayalalithaa had to resign twice as the chief minister owing to corruption cases, though she made strong comebacks and became the only leader to win back-to-back assembly elections in 2016 since Ramachandran did so three decades ago.
V K Sasikala: Jayalalithaa's close confidante for three decades, rising from a small-time entrepreneur offering video coverage services in the early 1980s. She got acquainted with Jayalalithaa in 1982.
Hailing from Mannargudi, a small town in southern Tamil Nadu, Sasikala won the confidence of Jayalalithaa and came to be known as her shadow, even with the late leader at her Poes Garden Residence till her death.
She took charge of the party after Jayalalithaa's demise and was elected general secretary and later the leader of the AIADMK Legislature Party in February, paving way for her elevation as chief minister of Tamil Nadu.
However, her conviction by Supreme Court in the 19-year-old disproportionate wealth case against, Jayalalithaa and two others, dashed her hopes of becoming the chief minister as she is now serving the remainder of her four-year jail term in a Bengaluru prison.
O Panneerselvam: An unassuming farmer-turned leader from southern Theni district and once considered a loyalist of Sasikala, was the Man Friday for Jayalalithaa, stepping in as the standby chief minister twice when she had to quit the top post.
He also shouldered the responsibility of heading the cabinet when Jayalalithaa was on prolonged hospitalisation last year and later became the chief minister after her demise.
However, days after proposing Sasikala's name for the AIADMK Legislative Party leader and resigning from the post, he revolted against her and alleged that he was forced to quit.
His late night dramatic announcement at the memorial of Jayalalithaa after a 40-minute long meditation in February caused a vertical split in the AIADMK.
He also raised doubts over the death of Jayalalithaa.
After days of uncertainty, marked by claims and counter claims of support by the two groups, the Sasikala faction propped up senior minister K Palaniswami as chief minister.
He later comfortably won a confidence motion in the assembly, dashing hopes of Panneerselvam who managed to rope in only a dozen MLAs out of the 132-strong AIADMK Legislature Party in the 234-member House.
TTV Dhinakaran: A nephew of Sasikala, he was re-inducted into the party and appointed deputy general secretary by her shortly before she proceeded to serve the jail term, apparently to keep the hold on the party with the family.
A former MP, Dhinakaran had been sacked along with Sasikala by Jayalalitha in December 2011 for anti-party activities.
Jayalalithaa later chose to revoke the expulsion of Sasikala alone.
Keen to secure popular support, he entered the fray in the April 12 by-poll to the RK Nagar Assembly constituency, which fell vacant due after Jayalalaithaa's demise.
The poll was later countermanded by the Election Commission over use of money to induce voters.
In a setback to him, Dhinakaran has been booked by Delhi Police on charges of attempting to bribe Election Commission officials for securing the 'Two Leaves' symbol of the AIADMK.
K Palaniswami: Another of Jayalalithaa, he was chosen as the chief minister by the Sasikala camp.
Born in an farmer's family in Salem district of Western Tamil Nadu, he swore allegiance to Jayalalithaa when AIADMK split into two factions in 1987, one led by her and the other by Ramachandran's wife Janaki.
Surprisingly, he has now jumped into the anti-Dhinakaran bandwagon, though choosing to field senior cabinet colleague D Jayakumar to make the public announcements in this regard.
Deepa: Niece of Jayalalithaa, Deepa is attempting to claim the legacy of her aunt.
At the height of the factional feud triggered by Panneerselvam, she announced formation of MGR Amma Deepa Peravai and took the plunge into electoral politics by nominating herself as the candidate in the now countermanded RK Nagar bypoll.
However, several of her supporters have switched to the Panneerselvam camp lately.
Though Deepa earlier announced she would work together with Panneerselvam, she later charted her own course.
Other players in the state politics include DMK's nonagenarian patriarch M Karunanidhi, who has become inactive due to age-related health problems.
His second son M K Stalin, long considered the political heir of Karunanidhi, has recently become the Working President of the Dravidian party.
Stalin's sister Kanimozhi is a Rajya Sabha member.
DMK, which has an alliance with the Congress and the IUML, has a combined strength of 98 MLAs and is closely observing the tremors in the AIADMK.
The BJP has been seeking to gain a foothold in the state and is led by doctor-turned politician Tamilisai Sounderajan.
Union Minister Pon Radhakrishnan, represents the saffron party from the state, in the Council of Ministers led by Prime Minister Narendra Modi.
Besides, there are handful of regional parties including the DMDK led by actor-turned politician Vijayakanth and PMK headed by doctors S Ramadoss and his son Anbumani Ramadoss, a former union health minister.
The MDMK party is led by Vaiko, who is now lodged in prison in a sedition case. He is a known supporter of the banned LTTE.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)