Guru Nanak was born in 1469, his parents were Hindu but from an early age he questionned religion and spent a lot of time meditating (even when he was meant to be helping his father on the land)
When he was 11 years old his father wanted him to take part in a Hindu ceremony where you get a sacred thread to wear, Nanak refused because he beleived people should be distinguished by the things they did not what they wear.
When he was older he got married to Sulakhani and had two sons. His father gave him money to start a business but he gave it away to feed the poor and needy and his father was very cross.
One day when he went to he water to bathe and meditate he disapeared under the water for two days, everyone thought he was dead but he reappeared on the the third day and said he had been given a message from god to share people.
He left his wife and family and went on four long journeys over 35 years.(north ,east,south and west) to spread the message god gave him" there is no muslim or Hindu just worship god we are all equal." This was the beginning of Sikhism -Oneness with God.
He became known as the "Guru" because of all of his teachings and they are written down in the Guru Granth Sahib. He started the Langar (communal kitchen) because he felt everyone should eat together. He died aged 70 in 1539 and gave his spiritual light to Angad Dev.