He is best-known as Roman Brady from 1981–84, and from 1991–94, on Days of Our Lives. In August 2005, Northrop returned to Days as a new character named Dr. Alex North. During this time the three actors who portrayed Roman Brady at one time all appeared. In both cases, he worked extensively alongside real life friend Deidre Hall (Marlena Evans) and, again in both cases, his characters were "killed" when they fell from a cliff on a tropical island.