The CCTA - Central Computer and Telecommunications Agency
The CCTA is widely recognized as having created the first version of ITIL. The original title was a lengthy one "Government Information Technology Infrastructure Management Methodology" (GITMM). The GITMM developed into 31 volumes.
April 2001 saw the CCTA merge with the OGC (Office of Government Commerce). The OGC is an branch of the United Kingdom's Treasury and it is quite likely that seeing the commercial value of ITIL(r) the Treasury were very keen to become involved.