Landau was born in
Philadelphia, the son of Robert Magee, who emigrated from
County Londonderry, Ireland and listed his occupation as a gardener on the 1880 census. His mother, Maryann, was Pennsylvania-born of Irish and English descent. Landau studied law at the
University of Pennsylvania. To improve his diction, he took a class in dramatics and later abandoned his law studies. He made his film debut in 1931. ==Personal life and death==