Sophus Lie (1842-1899) is one of Norways greatest scientific talents. His mathematical works have made him famous around the world no less than Niels Henrik Abel. The terms Lie groups and Lie algebra are part of the standard mathematical vocabulary. In his comprehensive biography the author Arild Stubhaug introduces us to both the person Sophus Lie and his time. We follow him through: childhood at the vicarage in Nordfjordeid; his youthful years in Moss; education in Christiania; travels in Europe; and learn about his contacts with the leading mathematicians of his time.Sophus Lie (1842-1899) is without doubt one of Norway's greatest scientific talents. His mathematical works have made him famous around the world no less than Niels Henrik Abel. The terms Lie groups and Lie algebra are today part of the standard mathematical vocabulary. In his comprehensive biography the author Arild Stubhaug let us come close to both the person Sophus Lie and his time. We follow him through childhood at the vicarage in Nordfjordeid, his growing up in Moss, school and studying in Christiania, travelling in Europe and his contacts with the leading mathematicians of his time. The academic and scientific career brought Lie from Christiania to Leipzig as professor, before the attempt to call him back to Norway, when she stood on the threshhold to national sovereignty, was successful.I The Measure of a Life.- Tracking Him Down: A Torrent of Stories.- II Family Background and Upbringing.- The Family Tree.- The Priestly Family at Nordfjordeid.- Fathers Home in Moss.- III School and Education.- Nissens School. Examen Artium.- Student Life.- The Lack of a Calling.- IV In Tune with the Times.- Into Mathematical History.- There was a Mathematician in Him.- The First Tour Abroad.- Parliamentary Professor.- V Professor in Christiania.- My Inner Life Has Been Most Mighty.- My Lifes Good Fortune.- Marriage at Last.- Herr Professor mit seiner Gemahlin.- In the Lee of the Modernl3-