festivals
What is Karthigai Deepam and why are lamps lit on hilltops during this festival?
The story behind the flame
At the heart of Karthigai Deepam is a story from the Skanda Purana. Brahma and Vishnu once argued over who was greater. Shiva appeared between them as a column of fire with no beginning and no end. Neither could find its top or its bottom. Through this, Shiva showed that he is beyond measure and beyond both of them. This form of Shiva as a limitless pillar of light is called the Lingodbhava. The great beacon lit on top of Arunachala hill in Tiruvannamalai is understood as a living sign of this same column of fire. The hill itself is seen as Shiva. The flame on its peak is not just a symbol. For devotees, it is Shiva made visible.
Where the festival comes from
Karthigai Deepam is one of the oldest festivals in Tamil tradition. It falls in the Tamil month of Karthigai, on the full moon night, which also lines up with the wider pan-Indian festival of Kartik Purnima. The Arunachala beacon at Tiruvannamalai is the most famous expression of the festival, drawing large numbers of pilgrims each year. But lamp-lighting on this night is also an old domestic custom across Tamil households, separate from the hilltop tradition.
What the lamps mean
Light runs through everything in this festival. At home, rows of small oil lamps are lit in doorways and courtyards. The flame is seen as auspicious, as something that drives away darkness in both a physical and a deeper sense. The hilltop beacon takes this further. A single great flame visible from far away stands for the idea that Shiva's presence is not hidden in a small place but radiates outward without limit, just as the story of the Lingodbhava describes.
How it is different from Diwali, and how it is kept today
People sometimes ask whether Karthigai Deepam is simply a Tamil version of Diwali. Both involve lamps, but they are different in their roots. Diwali's lamp-lighting is tied to stories like the return of Rama and the defeat of Narakasura. Karthigai Deepam's lamp-lighting is rooted in the Shiva-as-fire story and the Arunachala tradition. The theology behind them is distinct. Today, Tamil families in India and around the world mark the day by lighting lamps at home. Many make the journey to Tiruvannamalai to see the hilltop beacon. For those far from home, the domestic lamp-lighting keeps the festival alive as a personal and family observance.