This dissertation examines the decline and re-emergence of the Swiss mechanical watch industry from 1970-2008, exploring how, when, and why market demand for legacy technologies resurrect and reshape a mature field. Extending existing research on technology emergence and death, I reveal the dynamics of technology and field re-emergence. I focus on the mechanisms of identity and institutional change associated with re-emergence, as well as how institutional leaders and guardians serve as agents of change who simultaneously preserve and reframe the values and product conceptions associated with a legacy technology. Additionally, I advance the notion of identity ambidexterity by examining how organizations explore and exploit multiple elements of their identity simultaneously during such periods of instability. Using qualitative and quantitative methods, I analyze a wide range of interview, archival, historical, and observational data at the levels of the industry and the organization. More broadly, I seek to demonstrate how the reclamation of legacy identities reshapes the institutional environment of a mature field, and how incumbent firms re-define their organizational identities after a technological innovation threatens to destroy their dominant market position.