Adam and Eve have two sons, Cain and Abel. Cain slays his brother after God rejected an offering from him and asks the famous question, "Am I my brother's keeper?" God curses Cain and subjects him to being a wanderer on the earth. God put a mark on Cain to protect him from others. Cain meets a wife, has a son, Enoch, builds a city and names it after his son.
Artwork by Marc Chagall: Cain and Abel