Greater India was the historical extent of the culture of India beyond the Indian subcontinent. This particularly concerns the spread of Buddha Dharma and Sanathana Dharma, introduced by the travellers of the 5th to 15th centuries, but may also refer to the spread of Buddhism from India to Central Asia and China by the Silk Road during the early centuries of the Common Era. To the west, Greater India overlaps with Greater Persia in the Hindu Kush and Pamir mountains. The term is tied to the geographic uncertainties surrounding the "Indies" during the Age of Exploration.