Guru Nanak's first udasi began around 1500 when he made the momentous decision to leave his family, wife Mata Solakhani and two young sons and abandon his comfortable life in Sultanpur. This departure followed a profound spiritual experience where he disappeared for three days and emerged declaring "There is no Hindu, there is no Muslim," immediately challenging religious orthodoxy.

Accompanied by his Muslim companion Mardana, Nanak embarked on a fifteen-year journey spanning thousands of miles across India and beyond, reaching Mecca, Baghdad, and Tibet. This partnership itself was revolutionary, a spiritual teacher travelling with a Muslim musician demonstrated his commitment to transcending religious boundaries.

Throughout this 1st Udasi, Nanak systematically dismantled established religious conventions. He questioned Brahmin authority, rejected caste distinctions, and challenged empty ritualistic practices. At sacred sites, he deliberately violated orthodox customs, refusing ceremonial river worship, arguing that true purification came from within, not external rituals.

His radical message proclaimed God as the universal creator, accessible to all regardless of birth, gender, or social status. This egalitarian spirituality resonated with common people who found liberation in his teachings of direct divine communion without intermediaries.

The 1st Udasi transformed Nanak from householder to spiritual revolutionary, establishing the foundational principles of Sikhism: equality, devotion, and the rejection of religious divisions that would reshape spiritual understanding across the subcontinent.