Sigmund Freud, born in 1856 and later settling in Vienna, is recognized as the father of psychoanalysis, developing theories such as the interpretation of dreams and psychosexual development. His work introduced concepts like the unconscious mind, defense mechanisms, and the structure of personality, which includes the id, ego, and superego. Freud's contributions laid the foundation for modern psychology and emphasized the significance of early childhood experiences and the exploration of unconscious desires.