Veronica Halliwell
From Tardis Wiki, the free Doctor Who reference
Veronica Halliwell was the Director General of MI5 in the late 20th Century.
She was a key intelligence figure and worked with UNIT on many National Security issues. She answered to Home Secretary David Staines and briefed the Government on issues.
She was present during the alien invasion of Lord Xznaal and survived it. However the following year, she was assassinated by the Voracians and her death was investigated by Harry Sullivan.