Veerapandiya Kattabomman [Sivaji Ganesan] is the fearless chieftain who governs Panchalankurichi with a steady, protective resolve. When a robbery shakes his domain, he leads a covert pursuit with his loyal retinue, determined to bring the culprits to justice. The captured thieves confess that they were hired by the British to sow unrest, and that the neighboring chieftain Ettappan [V. K. Ramasamy] has been enticed to assist in annexing Panchalankurichi. This revelation sets the stage for a wider clash between a determined local leadership and colonial interests.
In the nearby village of Chayalkudi, Vellayamma [Padmini], known to locals as Vellaiyammal, vows to marry the man who can tame her pet bull. She travels with the beast to Panchalankurichi for a jallikattu event sponsored by Kattabomman, hoping to witness a display of courage. Among the challengers, Vellaiyathevan [Gemini Ganesan], Kattabomman’s trusted commander-in-chief, finally subdues the bull and wins her heart. When the king learns of their love, he blesses their union, seeing in their bond a reflection of the perseverance and honor he has long defended. The couple’s romance becomes a quiet beacon of hope amid looming tension with the British.
A formal appeal arrives from W. C. Jackson [Parthiban], the Tirunelveli tax collector, requesting a private audience at Ramanathapuram to discuss payment. Captain Davison, a British ally, counsels a cautious, measured approach, but Jackson uses the moment to humiliate Kattabomman and orders his arrest. Surrounded by British troops, Kattabomman fights his way to safety, though his minister, Thaanathipathi Pillai [M. R. Santhanam], is captured in the confrontation. The setback weighs heavily on the king and his inner circle, signaling the start of a more aggressive British strategy.
Some time later, Pillai is released and brings news that Jackson has been sent back to England on Davison’s recommendation. A British messenger to Tirunelveli, reporting to Colonel S. R. Lushington, accuses Pillai and his men of looting granaries and killing men at Srivaikuntam. Pillai defends his actions as a response to famine, but Kattabomman is unable to reconcile the act with his own code. Pillai apologizes and offers himself as a prisoner, yet Kattabomman refuses to hand him over; instead, he attempts to compensate the losses with money. Lushington rejects the gesture and, with Major Bannerman [Javar Seetharaman] and Ettappan’s help, stirs up neighboring rulers to join the assault on Panchalankurichi. Bannerman is placed in command of British forces, and the plan is to strike while the festival in Tiruchendur draws crowds away.
Sundaralingam [A. Karunanidhi], the king’s trusted adviser, warns that war is imminent. The kingdom braces for conflict as Sundaralingam mobilizes the people and resources needed to resist the probable onslaught. On the day the battle looms, Vellaiyammal pleads with Vellaiyathevan not to go, haunted by a nightmare she believes portends disaster. He goes anyway, and is killed in the ensuing clash. Grief-stricken, Vellaiyammal exacts vengeance by killing the man who took her husband’s life, only to fall dead beside his body soon after.
Bannerman’s artillery rains down on Panchalankurichi, and Kattabomman’s forces suffer heavy losses. The king sustains a wound to the neck, but his brother Oomaithurai [O. A. K. Thevar] shields him and helps him escape the advancing fire. Realizing the fort cannot endure another cannon barrage, Kattabomman and Oomaithurai flee to the neighboring kingdom of Kovilpatti. Pillai, disguising himself as Kattabomman, creates a decoy trail to mislead the pursuing British soldiers. From Kovilpatti, the fugitives press on to Pudukkottai, where Thondaimaan, the king there, is pressured by the British to capture them. Fearing the power of the imperial forces, Thondaimaan capitulates and hands the fugitives over.
Oomaithurai is imprisoned, and Kattabomman is subjected to a formal trial by the British, ending in his execution by hanging. The story closes on the sacrifice of a man who stood firm in the face of overwhelming odds, and a family’s enduring grief as the cost of resistance becomes monumentally clear.