Ultra, code name for high grade signal intelligence collected from encrypted radio messages, was established in 1940-1941. Work on Ultra was carried out at Bletchley Park, located in Milton Keynes, Buckinghamshire.
"...without a doubt Ultra made a big difference, sometimes a vital one ... It could sway battles and save lives, and it gave staffs and commanders an unparalleled insight into enemy dispositions, capabilities, and intentions."
- Peter Calvocoressi