The Buddha, also known as Siddhārtha Gautama, was a philosopher, mendicant, meditator, spiritual teacher, and religious leader who lived in Ancient India. He is revered as the founder of the world religion of Buddhism. He taught for around forty five years and built a large following, both monastic and lay. His teaching is based on his insight into duḥkha (typically translated as "suffering") and the end of dukkha – the state called Nirvana.