Despite the rapidly expanding ambit of physical research and the continual appearance of new branches of physics, the main thrust in its development has been the attempt at a theoretical synthesis of the entire body of physical knowledge. Vladimir Vizgin's work presents perhaps the first systematic historico-scientific study of the formation and development of the unified field theories in the general context of 20th century physics. Concentrating on the first three decades of the century and drawing extensively on Russian sources, the author analyses the first successes, failures and paths of further development of the unified field theories. He presents the evolution of these theories as a process of interaction/competition between the geometric field and quantum research programs, and ascertains the relevance of these theories for fundamental concepts in modern field theory.