Mahajanaka was an ancient prince who swam seven days and seven nights in turbulent seas, strung a bow that required the strength of a thousand men, and grasped the meaning of asceticism after encountering a plundered mango tree.
He is also the star of a musical and fireworks extravaganza being staged in the middle of a lake this week in downtown Bangkok.
Ask any Thai among the hordes queuing up for free tickets what the show is about and they will say: It's about our King.
King Bhumibol Adulyadej turns 87 today. The world's longest reigning monarch is convalescing in Bangkok's Siriraj Hospital - where he lived between 2009 and last year - at a time when the country's 20th Constitution is being drawn up under the yoke of martial law.
He and his family will meet well-wishers at the Grand Palace this morning, scuttling speculation about his ill health that followed the removal of his gall bladder in October.
The revered King holds considerable moral authority in a nation racked by almost a decade of political conflict.
Last year, as anti-government protesters waged a street battle with security forces to enter government premises, the animosity ebbed just before his birthday. Barbed wire was rolled back and the two sides hugged each other.
This year, with the military at the helm after throwing out the Yingluck Shinawatra-led government, open confrontation has been suppressed by strong surveillance.
As in the past few weeks, the rest of the month will be devoted to allegorical plays, exhibitions and nostalgic songs, as Thais don yellow clothes in the King's honour and sing the praises of someone they regard as a demigod and father of the nation.
At Siriraj Hospital yesterday, well-wishers bearing his portraits had already turned up, preparing to bed down for the night along the route to the Grand Palace where they could catch a glimpse of their beloved monarch.
Hundreds more have travelled for hours from different parts of the kingdom to prostrate themselves before a giant portrait in a hospital hall. They include Ms Suwimon Wongwai, 48, a vegetable seller who had travelled from Petchaburi province, more than 100km south of Bangkok.
"I was worried whether his condition would deteriorate," she told The Straits Times. "I followed all announcements of his health very closely."
This is the time of the year when Internet home pages of Thai firms are overlaid with a picture of King Bhumibol. Television airtime is packed with snippets of the King playing the saxophone or trekking up hills for rural development work in his younger days.
On Tuesday, Thailand's Ministry of Foreign Affairs and the Indian Embassy in Bangkok opened an exhibition featuring the work of King Bhumibol alongside that of India's independence fighter Mahatma Gandhi.
"Great men who work for the majority of the people have similar thoughts," declared co-curator Priyanut Dharmapiya. "Mahatma Gandhi emphasised on self-reliance, which is similar to His Majesty's sufficiency economy philosophy."
Historian Thanet Aphornsuvan says: "There have been many important changes in the country during his reign, including the expansion of political and social awareness."
King Bhumibol's public appearance today is taking place amid great national uncertainty, with an International Crisis Group report warning of greater conflict ahead, as well as a widening probe into alleged police corruption that implicates relatives of Crown Prince Maha Vajiralongkorn's wife, Princess Srirasmi.
Many will no doubt be paying close attention to what he says.