Erik Erikson (1902–1994) was an influential stage theorist who expanded on Sigmund Freud's psychoanalytic work. His journey into psychoanalysis began in Vienna after meeting Anna Freud, who encouraged him to study the field. He earned his diploma from the Vienna Psychoanalytic Institute in 1933 before immigrating to the United States to escape the rise of Nazism. Erikson is most famous for his psychosocial theory of development, which asserts that personality is shaped by social interactions throughout a person's entire life.