In recent decades, the 'safety' of patients and staff has become a pressing concern in the British National Health Service (NHS). However, little is understood about how and why these ideas and practices evolved historically, and were spread throughout the NHS. My project, Hazardous Hospitals, addresses this lacuna by exploring ideas and practices around 'safety' in NHS general hospitals from 1960-2012. It analyses the development, promotion and institutionalisation of 'safety cultures': ideas, values and behaviours around safety, as well as the systems and processes which support and sustain them. My outputs will be a major monograph exploring the history and meaning of 'safety' in the NHS, an article in History & Policy, as well as 2-3 journal articles exploring sub-topics, such as occupational health. I ask: 1. What defines the ‘safety culture’ of NHS hospitals? How can these ‘safety cultures’ vary? 2. How was safety in hospitals assessed, and in what ways did it come to the attention of NHS managers and policymakers after 1960? 3. How did NHS managers promote safety among their staff? 4. What role did groups such as patient organisations, safety campaigners and the press play in depicting, challenging and promoting reform of hospital ‘safety cultures’? The publication of the Francis Report (2013) into healthcare failures at the Mid Staffordshire NHS Foundation Trust dramatically refocused public and political attention on issues of 'safety' in the British NHS. ‘Safety’ has increasingly occupied the attention of policymakers in recent decades, with hospital managers establishing various systems and processes to protect patients and staff from harm. These include alert systems, policies around patient consultation, and campaigns for preventing harms such as falls and healthcare-associated infections. However, little is understood about how and why these ideas and practices around ‘safety’ in the NHS evolved. My project explores the history of safety in the NHS, highlighting how hospitals have promoted ‘safety cultures’: ideas, values and behaviours which support safety. Drawing upon a rich seam of archival material, and a distinctive methodology which visualises hospitals in a systematic way, my project makes a timely contribution to historical understandings of the NHS.