Bhai Mardana Ji (Punjabi: ਭਾਈ ਮਰਦਾਨਾ) (1459–1534) was the first Sikh and longtime companion of Guru Nanak Dev, first in the line of gurus noted as Sikh. Mardan accompanied Nanak on his journeys across India and Asia. Mardana was born in a Muslim family, to a Mirasi couple, Badra and Lakkho, of Rai Bhoi di Talwandi, now Nankana Sahib of Pakistan.
It is said that Mardana first contacted Guru Nanak to seek help as many people in his family were dying at a young age. Guru Nanak approached the family and had seen that Mardana's mother was crying because she felt her son will die. Mardana's mother told Guru Ji that the reason she was crying is because all her children were dying. Following this, Guru ji asked what her son's name was, to which she responded "MarJana" meaning "He will die". Guru Nanak kindly asked the mother if she is willing to give him her son so that she will not have to bear the burden of her child's death. The mother accepted this and gave her son to Guru Nanak to take care of. As a result of this, Guru Nanak gave Mardana the assurance that henceforth people in his clan will not die early. It is said that the name Mardana came from this assurance- Mar- Da- Na meaning 'Does not die'.
Guru Nanak and Mardana were brought up in the same village. The Miharban Janam Sakhi says that Mardana was ten years elder to Guru Nanak and was his companion since his childhood days. It further states that Mardana sang hymns written by Kabir, Trilochan, Ravidas, Dhanna and Bern. According to Ratan Singh Bhangu, Prachin Panth Prakash, Guru Nanak as a small boy gave Mardana a string instrument improvised from reeds to play on while he sang the hymns.
When Guru Nanak took charge of the granaries and stores of the Nawab of Sultanpur Lodhi, he became known for his generosity. Mardana, was by then married and had two sons and a daughter, Mardana went to meet Guru Nanak as Guru Nanak's father wanted news of his son, Mardana never went back from his trip and was with Guru Nanak from then on. He used to play the Rabab (r-aa-bab ) or rebeck as Guru Nanak spoke/sang his words about God.