Rath Yatra: The legend behind world's largest chariot festival

One of India's biggest religious festivals, the Jagannath Puri Rath Yatra, gets under way on Thursday. The festival is unique in that three Hindu gods are taken out of their temples in a colourful procession to meet their devotees. The BBC's Priyanka Pathak explains the legend behind the festival and its significance.

The biggest of these processions takes place in Puri in the eastern state of Orissa, while the other takes place in the western state of Gujarat.

Believed to be the oldest Rath Yatra or chariot procession in the world, this festival marks the annual ceremonial procession of Lord Jagannath, his elder brother Balabhadra and younger sister Subhadra, from their home temple to another temple, located in what is believed to be their aunt's home.

This journey is documented in undated Hindu sacred texts known as the Puranas which are believed to have been written a few thousand years ago.

This is the only festival in the world where deities are taken out of temples to travel to devotees, and it is also the largest chariot procession in the world.

Millions of people come to watch as a "king" sweeps the road with a golden mop and three massive 18-wheeled chariots bearing the sibling deities make their way through massive crowds. Their chariots, which are mini architectural marvels, are constructed over 42 days from over 4,000 pieces of wood by the only family that has the hereditary rights to make them.

Legend says it always rains on the day of the procession. For a whole week before, the temple doors are shut and no one is allowed inside, because it is believed that the sibling deities have a fever after bathing in the sun with 108 pitchers of water. The breaking of their fever calls for a change of scene, which is why they go to their aunt's home for a few days.

The size, pomp and splendour of this procession has even contributed a word to the English dictionary: Juggernaut.

Unlike the ornate, carefully crafted metal idols everywhere else, these three deities are fashioned from wood, cloth and resin. They are malformed with large heads and no arms: reminders of the legend of an impatient King.

The legend begins in different ways.

One speaks of an arrogant Indrayumna, King of Puri in the east, who tried to steal the Hindu god Krishna's heart. It had been immersed in the legendary Dwarka sea after his cremation and had reappeared to the tribes people of the place as an idol. When Indrayumna tried to claim its possession, the idol disappeared. The repentant king sought absolution from Krishna by sanctifying him in another form.

Another speaks of how Krishna's grief-stuck siblings - his elder brother Balabhadra and younger sister Subhadra- rushed into the Dwarka sea carrying his half-cremated body. At the same moment, King Indrayumna dreamed that Krishna's body had floated back up on his shores as a log.

The two legends merge here: Indrayumna decided to build a temple to house the log. His next task was to find someone to craft the idols from it. Legends say that Vishwakarma, God's own architect, arrived as an old carpenter. He agreed to carve the idols, but on the condition that he was not to be disturbed. However, when he did not emerge from his workshop for weeks, going without food, water or rest, a worried and impatient King threw the door open.

At the time the images were only half-finished, but the carpenter disappeared. Still, believing the idols to be made from the very body of God, the King sanctified them and and placed them in the temple.

When the deities disintegrate, they are remade in the same half-done image with new wood every 12 years. They were last remade in 2015.

Dwarka in Gujarat - where Krishna's half-cremated body is believed to have been immersed into the ocean - is located on the west coast of India and Puri in Orissa- where it is said to have re-emerged as a log - is located in the east.

About 500 hundred years ago, a travelling Hindu saint and temple priest of a Hanuman temple in Gujarat, Shree Sarangdasji, arrived in Puri to offer prayers at the historic Jagannathan temple.

While sleeping at the temple guest house, it is believed that he received visionary instruction from Lord Jagannathan to go back to Ahmedabad in Gujarat and install three idols of Jagannathan, Balbhadra and Subhadra there. Carrying out the instructions received in his dream, he founded the Ahmedabad Jagannathan Temple.

By doing so, he sanctified the two locations - one where Krishna's mortal remains began their journey from the west, to their transformation as Puri's Lord Jagannathan in the east.

About 142 years ago, one of the founder's disciples, Shree Narsinhdasji Maharaj, began the Ahmedabad Rath Yatra. The deities on chariots, pulled by elephants and humans, replicate their own journey in Puri, completing a set of rituals that sanctify the two places where Krishna's mortal remains are believed to have come to rest.

At the end of the festival, the chariots are dismantled and their wood is used as fuel in the temple kitchens - believed to be the largest in the world that cook 56 things every day and feed anywhere between 2,000 to nearly 200,000 people.

The elephants are returned to the lands managed by the temple trusts to roam free - until the procession the following year.

This year's festival was, however, marred by controversy over the elephants.

Following the death of some of the temple elephants in Gujarat, there was massive outcry over plans to replace them with elephants from the north-eastern state of Assam.

The four elephants would have had to make a perilous train journey of more than 3,100km (1,926 miles) in heatwave conditions to participate in the festival.

This decision was suspended by a wildlife official after activists went to court.