A portrait of Basavana, the radical poet and religious guru from the 12th century, whose words have inspired many other Indian poets, writers and dramatists. Professor Sunil Khilnani tells the story of a man whose deceptively simple verses protest against the immorality of the caste system and proclaim the intrinsic value of people who happen to be born poor. "His verses ... are what best explain him. They have a directness that reveals to us a free thinker, social reformer and religious evangelist who sometimes struggled to resist worldly temptations," says Professor Khilnani. Basavana was an inspiration to his followers yet his life came to a bitter end. His teachings are kept alive by a substantial religious community called the Lingayats who are concentrated in Northern Karnataka.

Produced by Mark Savage

Rajaraja was not the first of the Chola dynasty but he took their empire to its zenith - from a relatively small kingdom to the dominant empire in India. Professor Sunil Khilnani, from the King's India Institute in London, visits Tamil Nadu where he finds modern day connections with the ruler whose name means 'king of kings'. Professor Khilnani visits the temple at Thanjavur which Rajaraja built a thousand years ago and named after himself, utilising the profits of trade. "For Raja Raja had pulled off something that no Indian ruler before him seems to have done," says Professor Khilnani. "He'd commandeered trading boats, timber sailed craft and launched maritime expeditions, bringing far flung wealth back home." The king was lavish with his gifts and used his wealth to capture the imaginations of those he ruled. His most important gift to art history came at the temple's consecration: 60 portable icons of Lord Shiva, the Hindu deity.

Producer: Mark Savage

Is that a snake or a coiled rope? Intriguingly, that is the question which starts Professor Sunil Khilnani's look at the life and legacy of Adi Shankaracharya, the philosopher and theologian who set Hinduism - the third largest religion in the world - on a new course. Shankaracharya's ambition was to provide a unified, coherent, single reading of the Hindu scriptures. His teachings were not universally embraced but they were revived by Indian nationalists looking for a muscular response to the monotheistic religions of Christianity and Islam. His efforts to capture the oneness of the universe produced beautiful, sometimes enigmatic sentences - as elusive as the man himself. "I am neither earth nor water nor fire nor air nor sense-organ nor the aggregate of all these," wrote Shankaracharya, "for all these are transient, variable by nature."

Produced by Mark Savage

Professor Sunil Khilnani, from the King's India Institute in London, explores the life and legacy of Aryabhata, the legendary Indian mathematician and astronomer. Unknown in the West until a few decades ago, he is said by some to rank with Euclid and the great Greek mathematicians and astronomers such as Ptolemy. But unlike Euclid, Aryabhata left no proofs, explaining how to recreate his findings. "His ideas, translated into Arabic, influenced Islamic astronomers and mathematicians. But he wasn't working in the idiom of his Western counterparts, so his ideas didn't feed into the global stream of scientific discovery, and eventually Indians forgot Aryabhata too. It was only when science and technology began to flourish in modern India that his reputation got a relaunch," says Professor Khilnani.

Producer: Mark Savage

Professor Sunil Khilnani visits a modern-day clinic which follows the practices set out by Charaka, a medical pioneer whose handbook is still widely used in India today. His text, known as the Charaka Samhita or 'Compendium of Charaka', is an encyclopaedic work covering different aspects of health and how to live a good life. Ayurveda is the best known of the Indian subcontinent's three indigenous medical traditions and continues to be an important adjunct to India's national health system. Today, it is part of government policy and a ministry funds Ayurvedic training and care. Charaka believed that health depended on the balance of basic humours - wind, bile, phlegm - and that "if these elements are disturbed from their proper bodily locations, illness follows. Such disturbance often occurs through our own thoughtlessness, what Charaka calls 'violations of good judgement'."

Produced by Mark Savage

Professor Sunil Khilnani of the King's India Institute in London looks at the life and legacy of the emperor Ashoka, who ruled over a large part of the Indian sub-continent. He came to power around the time the Romans were fighting Carthage and the Chinese were building their Great Wall but faded from view over time. Rediscovered by the British, he went on to become an inspiration to India's nationalists. Ashoka's symbol of four lions, each facing in a different direction, can be found on official Indian documents and the nation's currency. His most remarkable legacy is the rock edicts, public instructions to his people on correct behaviour - including religious tolerance and his own principle of Dhamma. "Dhamma described the ruler's duty to interest himself in the welfare of his people, their health and happiness. It even committed him to planting banyan trees and mango groves along the roads, to provide water and resting places for travellers . . an early statement about the private faith of a leader and the responsibilities of public office"

Professor Sunil Khilnani, from the King's India Institute in London, looks at the life and legacy of Kautilya, whose treatise on political power dates back at least two thousand years. The Indian political strategist has been compared to Machiavelli. Some say he is more ruthless. Kautilya's text, written on dried palm leaves, lay forgotten for more than a millennium until it turned up at a library in Mysore at the turn of the twentieth century, providing inspiration for early Indian nationalists. "The discovery summarily exploded a Western cliché: that Indians were primarily ethereal, spiritual thinkers," observes Professor Khilnani. "Here was a strategic text--focused on worldly ends, advocating ruthless means to achieve power."

Professor Sunil Khilnani, from the King's India Institute in London, looks at the life and legacy of Panini, a master of the ancient Sanskrit language who lived around two and a half thousand years ago. His grammar, known as the Astadhyayi, had a lasting impact and helped to make Sanskrit the lingua franca of much of Asia for more than a thousand years - not through conquest or colonisation but because it served a purpose. Panini's grammar relied on a system that functioned like a powerful algorithm, or a computer programme today. He created, "in a mere forty-pages, the most complete linguistic system in history and helped to make Sanskrit the lingua franca of much of Asia for more than a thousand years".

Professor Sunil Khilnani of the King's India Institute explores the life and legacy of Mahavira Jain. Born more than two thousand years ago, Mahavira is the inspiration for millions of followers of the Jain religion. It teaches that the way to liberation and bliss is to live a life of non-violence and renunciation. At its heart is a belief that the entire world, from the ground we tread on to the air we breathe, is filled with life: our duty is to protect this universe of living souls through non-violent action. Mahavira is the last in the line of Tirthankars, beings who were said to be able to cross over from the world of human suffering into the realm of spiritual liberation. Unlike the other Tirthankars, we can be certain that he existed. "Mahavira asked his followers to renounce untruths and sex, to give up greed and attachment to worldly things - and stop all forms of killing or violence," says Professor Khilnani. "In short, the normal, devious, grasping and aggressive self had to be conquered."

Over the course of 50 episodes, Sunil Khilnani, director of the King's India Institute in London, takes listeners on a whirlwind journey from ancient India to the 21st century through the prism of the life stories of 50 remarkable individuals. He will also explore their surprising afterlives, which illuminate both the astonishments and urgent conflicts of India today. He begins with the Buddha, exploring the story of his life and how he has been reinvented in modern India by those who oppose the caste system. "Buddha's solution to suffering lay in the individual mind. But he was also sketching a new form of society," says Professor Khilnani. "He was a moral meritocrat, and to an extent a social one too."