Guru Nanak was the founder of Sikhism and the first of the ten Sikh Gurus. He lived from 1469-1539 and was born in the city of Talwandi, which is now known as Nankana Sahib in modern-day Pakistan. Guru Nanak was a spiritual teacher and philosopher who emphasized the importance of living a life of truth, compassion, and devotion to God. His teachings have been preserved in the form of hymns and verses in the Sikh holy book, the Guru Granth Sahib.