BAE Systems is the UK’s largest defence and security firm and one of the world’s major arms companies. It has changed from a state-owned aerospace firm to a privatised specialist defence company involved in a range of air, land, sea and cyber systems with a major presence in the US defence market. This article describes and assesses the history of the company, its organization, conduct and performance. <bold>Editor’s Note</bold>: This is the first of a new series of company surveys which describe the evolution and performance of the world’s major defence companies and other important defence companies which might be less well-known. Authors are invited to submit outline proposals (one page) for company surveys to the Editors.