To capture the escaped Cholas and the stolen idol, the Pandyas extend their invasion to unexplored territories, but are unable to find them.

Centuries later, in 2008, Indian archaeologists are searching for the secret land of the lost Chola group using clues left by the ancient Pandyan warriors, but the searchers always disappear.

After the sudden disappearance of archaeologist Chandramouli, the government organizes a search expedition led by the cruel and arrogant officer Anitha to find him and what became of the Cholas.

Under the influence of black magic, they are almost driven mad, and surrender to the follower, who reveals himself as the aged Raja Guru, the royal advisor who was sent away 800 years ago.

They are living in poverty and suffering from drought while awaiting the arrival of the messenger who, it is foretold, will lead them back to their motherland of Thanjavur.

The minister sponsoring the expedition and Army officer Ravishekaran, who escaped the traps and is the sole survivor of the expeditionary force, are also revealed to be Pandyas.

Anitha attempts to seduce the king and to persuade him to march immediately to the homeland so he can be formally crowned there, but he grows suspicious since her actions do not match the traditions about the messenger.

Giving up on persuading the king, Anitha attempts to kill the Raja Guru and poisons the wells, then hypnotizes a Chola girl into passing information to Ravishekaran, who returns with reinforcements.

Muthu then breaks free from his shackles, and saves the king's son, the last remaining heir of Chola dynasty.

[12] The film was stalled in early 2007 due to cinematographer Arvind Krishna's decision to leave White Elephants and the project was eventually shelved.

[13] In July 2007, Selvaraghavan announced a new film with a new team of Karthi and Reemma Sen in the cast, with Ramji replacing regular Arvind Krishna as the cinematographer.

[2] Erum Ali, wife of actor Abbas, became the team's head costume designer,[15] whilst Selvaraghavan's sister-in-law and Rajinikanth's daughter, Aishwarya Dhanush, was signed on as an associate director.

The producer was announced to be R. Ravindran whilst Yuvan Shankar Raja was appointed as music director following five previous successful soundtracks in Selvaraghavan films.

[18] After extensive development and pre-production which took four months for scripting,[19] the film started the first schedule in the forests of Chalakudy in Kerala with Karthi, Reemma Sen and Andrea during October 2007.

[21] In the studios, choreographer Shivshankar composed a classical dance for Reemma Sen and Parthiepan, and the sequence was shot over twenty days.

[23] Shoots in all regions were tough and demanding for the crew as the film featured more than three thousand junior artistes from a variety of unions across India, with the language barrier becoming a problem.

In March 2008, after filming had already begun, music director Yuvan Shankar Raja was ousted from the project due to differences of opinion.

During production, news websites had linked Selvaraghavan romantically with Andrea Jeremiah, to the pair's displeasure;[11] in August 2009, he divorced his wife, Sonia Agarwal.

[27] During the period, G. V. Prakash Kumar and Selva also worked on the music in Mumbai whilst re-recording was also held in Austria and London.

[22] Aayirathil Oruvan languished in production hell due to slow progress of the shoot and the extensive pre- and post-production works, with release dates being postponed for a total of a year.

[22] The soundtrack to Aayirathil Oruvan was released on 4 November 2009 at a University Auditorium in Chennai, in a critically praised event.

The remix version of "Atho Andha Paravai" from the 1965 Tamil film Aayirathil Oruvan was not included in the soundtrack release due to the rights of original song are held by Saregama music label, despite being featured in the film.Aayirathil Oruvan is considered as one of the longest films in Tamil cinema, with an original running time of 181 minutes (3 hours, 1 minute).

[34] Towards the end of the year, the film began to announce release date of Christmas which was later further delayed to coincide with the Pongal festival.

[38][39][40][41] Sify cited that the film represented "something new in the placid world of Tamil cinema", adding that it "broke away from the shackles of the stereotypes".

Selvaraghavan also was praised by the reviewer with claims that "the director transports us to a whole new world and at the end of it all, we are dumb struck by the visuals, the packaging and the new way of storytelling".

[49] On 1 January 2021, Selvaraghavan released the first-look poster for the sequel Aayirathil Oruvan 2, confirming that it would star Dhanush.