He was of the Iron Mountain sept of the Taardad Aiel. He was said to be the youngest clan chief in memory. He was a charismatic and gifted leader who not only ended a blood feud between his clan and another but was said to be close to ending the blood feud between the Shaarad and Goshien. He was chosen to lead the Reyn, Nakai, Taardad, and Shaarad to the Westlands to claim Laman's bloodprice in the Aiel War.
During the Aiel War, it was discovered that the maiden Shaiel/Tigraine Mantear had become pregnant with his child. Maidens are forbidden to carry the spear while pregnant by law, but Janduin was deeply in love with her and unwilling to make her obey the law. In the Battle of the Shining Walls, she died giving birth to their son, Rand al'Thor. Janduin, believing both his lover and child were dead, could not forgive himself and forsaking his place as clan chief journeyed into the Blight to slay shadowspawn. It was said he encountered a man who looked like Tigraine, undoubtedly Luc Mantear/Slayer and refused to lift his spear when he was killed.