This paper discusses the results of a research study in the use of architectures in government agencies. The paper uses archival and time line analysis to present the context for securing the vast stores of protected government information, including the actions taken by the Australian government leading into the terrorist attacks of 11 September 2001 (termed 9/11), and the government reactions post 9/11. The results show that at the strategic level, the Australian government commenced a process of examining information security vulnerabilities and establishing a security architecture only to terminate the initiative due to a lack of budgetary funding. Also, a qualitative research method was used to examine the security architecture implemented in a large government agency. Results from the agency case study demonstrate that security architectures form part of the fabric of the agency’s business, not only in terms of information and communications technology infrastructure, but also staff behaviours and attitudes to securing information stores and exchanges.