Guru Nanak was the founder of Sikhism.

Guru Nanak:
Guru Nanak Dev Ji was born in 1469 in the Punjab region of South Asia, which is now part of Pakistan. He was the founder and the first Guru of Sikhism. Guru Nanak was born into a Hindu family and was deeply influenced by both Hindu and Muslim teachings. However, he wanted to create a new path that would bridge the gap between these two religions.

Teachings:
Guru Nanak preached the idea of "Oneness of God" and rejected the caste system, idol worship, and rituals that were prevalent in both Hinduism and Islam. He emphasized the importance of living a truthful and honest life, and he believed in the equality of all human beings. Guru Nanak traveled extensively and spread his message through his teachings, hymns, and poetry.

Key Principles:
Guru Nanak's teachings revolved around three main principles:

1. Naam Japna: This refers to the practice of remembering and meditating on God's name. Guru Nanak believed that by constantly remembering God, individuals could overcome their ego and attain spiritual enlightenment.

2. Kirat Karni: This principle emphasizes the importance of honest living and hard work. Guru Nanak taught that individuals should earn their livelihood through honest means and should share their blessings with others.

3. Vand Chakna: This principle promotes the concept of sharing and giving to others. Guru Nanak believed in the importance of selfless service and helping those in need.

Sikhism:
Guru Nanak's teachings laid the foundation for Sikhism, a monotheistic religion that emerged in the 15th century. Sikhism combines elements of both Hinduism and Islam but also has its unique beliefs and practices. The followers of Sikhism, known as Sikhs, believe in the teachings of Guru Nanak and the subsequent nine Gurus who came after him.

Conclusion:
In conclusion, Guru Nanak was the founder of Sikhism. His teachings emphasized the importance of spiritual enlightenment, honest living, and selfless service. His message continues to inspire millions of Sikhs around the world, and Sikhism has become one of the major religions in South Asia.