Kannagi was Puhar's merchant 's daughter, and ship captain Manayakan. She marries Macattuvan 's son, Kovalan, whose family was sea traders and had Manimekalai, the sea goddess, as patron deity. Kovalan met a dancer Madhavi later, and had an affair with her that led him to spend all of his money on the artist. Kovalan realized his mistake at last, penniless, and returned to his wife Kannagi. By selling Kannagi 's precious anklet, Kovalan hoped to recoup his fortunes by trade in Madurai.
Madurai was ruled by Nedunj Cheliyan I, king of Pandya. When Kovalan attempted to sell the anklet, it was mistaken for the queen's stolen anklet. Kovalan was charged with stealing the anklet and was subsequently beheaded without trial by the king. She became enraged when Kannagi was informed of this, and set out to prove the king's innocence to her husband.
Kannagi came to the court of the king, broke the anklet seized from Kovalan and showed it contained rubies as opposed to the anklets of the queen containing pearls. Realizing the fault, the king committed shameful suicide, after delivering such a huge miscarriage of justice. Kannagi uttered a curse that Madurai's entire city be burned. Pandyas' capital city was set ablaze which resulted in huge losses. She calmed down, however, at Goddess Meenakshi 's request, and attained salvation later. The story forms Silapathikaram's crux, written by poet Ilango Adigal.
Kannaki Amman is eulogized as the epitome of chastity, and worshiped in selected regions as a goddess. She is worshiped by the Sinhalese Buddhists as goddess Pattini in Sri Lanka, by the Sri Lankan Tamil Hindus Kannaki Amman, and by Kodungallur Bhagavathy & Aatukal Devi in Kerala, South Indian state. Keralites believe that Kannaki is an incarnation of Goddess Bhadrakali who entered Kodungalloor and got salvation in the temple of Kodungalloor.