This 1976 film based on the Jack Higgins novel involves a German commando team's effort to assassinate Prime Minister Winston Churchill, by successfully infiltrating an English town.
A lot of then-(and still) famous stars make up the cast, including Michael Caine, Donald Sutherland, Robert DuVall, Jenny Agutter and Treat Williams. Larry Hagman brilliantly plays a US "desk jockey" itching for a combat mission, who gets in over his head almost from the get-go.
Action in this film was believably choreographed, with loads of realistic collateral damage not often seen in war/action films... when I first saw this film as a young teenager around 1980, I was impressed by the fact that it even bothered to show blast effects from a simple hand grenade, without a ton of fiery pyrotechnics so many movies of the day (and even to this day) seem to thrive upon.
The story is generally good, and after a somewhat slow start, once the assassination plot (and efforts to head it off) get moving, the pacing is pretty good.
I passed up getting this on dvd a year or so ago, because it came as a "double feature" set (with a dvd of Hamburger Hill... why not another WWII film instead?) and I couldnt tell what any of the features of the dvd were. (I was also out of money at the time, and never saw the set after that.) I'm glad I waited, since I found a single copy for less than $10US just last week, and it's even letterboxed. Also included is a fairly long text biography of Churchill, so you get real history with the fiction.

I wonder if they ever considered filming the sequel The Eagle Has Flown?