Though there are many plausible candidates for the title of `first manufactured computer', it's fair enough to call the Colossus machine built at Bletchley Park an `early computer'. In January of 1944, the Colossus Mk 1 began breaking messages encoded with the Nazi's Enigma cipher within hours of their interception. By the end of the war, 63 million characters of German messages had been recovered by ten Colossus machines [Sale, 1998].
This war-torn period is the age of innocence in this story because the computer itself knew nothing of the conflict; it was unaware of allies or axis, of friends, enemies, or spies. It was completely open and at the mercy of whoever could reach the main plug panel next to the paper tape reader. Of course, buried deep in F Block on the ground of the top-secret Bletchley Park operation, such naive trust was both reasonable and efficient.