For a millennium and a half, from about 250 BC to 1200 AD, India was a confident exporter of its diverse civilisation, creating around it a vast empire of ideas, an 'Indosphere' where its influence was predominant. During this period, the rest of Asia was the willing recipient of a mass-transfer of Indian soft power. Indian art, religions, technology, astronomy, music, dance, literature, mathematics, and mythology blazed a trail across the world, along a Golden Road that stretched from the Red Sea to the Pacific, connecting different places and ideas to one another.

Like ancient Greece, ancient India came up with a set of profound answers to the big questions about what the world is, how it operates, why we are here and how we should live our lives. Out of India came holy men, monks and missionaries as well as pioneering merchants and artists, astronomers and healers, scientists and mathematicians. The Golden Road highlights India's oft-forgotten position as a crucial economic and civilisational hub at the heart of ancient Eurasia.

Multiple award-winning historian William Dalrymple gives a name to this spread of Indian ideas that transformed the world; crossing political borders and influencing everything they touched, from statues of Indian ascetics erected in Roman seaports to Cambodian friezes of the Mahabharata, from the Buddhism of Japan to the Hindu rituals of Bali, from the echoes of Sanskrit poems found in Chinese poetry to the discovery of the algorithm and the observatories of Baghdad.

Over half the world's population lives in areas where Indian religions and culture are, or once were, dominant. Meanwhile India's intellectual influence travelled far to the West, giving us not only crucial mathematical concepts such as zero, but also the very numbers we use to this day: arguably the nearest thing humanity has to a universal language. Drawing from a lifetime of scholarship, Dalrymple argues that India is the great intellectual and philosophical superpower of ancient Asia.