Festival story · 4 tellings · North India, South India, The Himalaya
Indra's pole: the banner festival and Indra Jatra
Why a pole is raised for Indra: the Mahabharata's gift to King Vasu of Chedi, Kathmandu's legend of Indra the captive flower thief, and the Tamil Indra festival at Puhar.
Vasu of the Paurava line, ruler of Chedi by Indra's advice, turns ascetic. The gods, fearing for their headship, coax him back; Indra praises Chedi and gives him a crystal car that courses through the air, a garland of unfading lotuses that protects in battle, and a bamboo pole. After a year the king plants the pole in the ground, adorns it with golden cloth, perfumes and garlands and worships Indra; Indra accepts the worship in the form of a swan and promises victory and prosperity to kings and people who keep his festival. Since then kings raise the pole.
The Himalaya · Kathmandu Valley, NepalFolkNewar🪔 Indra Jatra
Indra comes down to the Kathmandu Valley, hidden in cloud and looking like an ordinary man, to pick parijat flowers his mother needs for a rite. The townspeople catch him, bind him hand and foot like a thief and display him. His elephant searches the streets; his mother descends and reveals who he is. Released, the people are granted that she take the souls of that year's dead to heaven, and she adds the morning mist of autumn and winter that ripens the crops. In Doig's telling the chain of souls holding her garment breaks and they fall into a mountain lake. The festival raises a pole from Nala, shows bound Indra images, runs the wicker elephant Pulu Kisi and walks the Dagin procession.
What is different here:
No king and no gift from Indra: the god is a captive, the people win the boons, and the festival also serves the dead. The pole is cut in a forest, not given.
The Himalaya · Bhaktapur and Khokana, NepalFolkNewar🪔 Indra Jatra
The encyclopedia article notes that Bhaktapur keeps the days differently, with Yama Dyah poles, sky lamps and a procession to the pond Siddha Pokhari, traditionally linked with the name Indra Daha, and that Khokana raises its own pole with statues of Indra.
What is different here:
Town variants of the same festival; the lake of the legend is identified with a town pond.
South India · Puhar (Kaveripattinam), Tamil NaduBuddhistTamil
Canto 1 of the Buddhist Tamil epic says a Chola king, on the advice of Agastya of the Malaya hill, obtained that Indra be present in Puhar for twenty-eight days each year. The elders fear that the guardian deities of the square and the bazaar will trouble the city if the festival is forgotten. The drum is taken from the temple of the thunderbolt, set on the royal elephant and beaten to announce it; citizens are told to decorate streets, spread fresh sand, hoist flags and keep the peace while gods and men move about together.
What is different here:
A city festival of twenty-eight days tied to a sage's advice and to the city's safety; announced by drum, with no pole legend. Secondary summaries add that the sea took Puhar when a later king neglected it.
Sources: The Mahabharata, tr. K. M. Ganguli (1883-96), sections read for the Vedic layer; The legend behind the myth of Indra Jatra, Desmond Doig, Nepali Times (republished 31 August 2020); Wikipedia: Indra Jatra; Manimekhalai, Book I: Indra's Festival (English rendering hosted at Ancient Buddhist Texts; translator not named on the page); Wikipedia: Indra Vila