Michael Caine’s breakout role as a film actor was in the film Zulu (1964), in which he played Lieutenant Bromhead, a young upper-class officer with a snooty accent.
Caine recalls that, “in Zulu I was cast as a wishy-washy upper-crust Victorian officer. Now, I wasn’t in a very strong position to make radical suggestions about interpretation. I had got the part by the skin of my teeth. Originally I’d gone to audition for the part of a Cockney private, but they’d already cast that role. However, since I was tall and fair, I apparently looked like a posh Englishman, and the director, Cy Endfield, asked if I could do an upper-class accent. I switched quickly to Etonian and said, ‘Why, Mr. Endfield, I’ve been doing it for years.'” — Michael Caine, Acting in Film: An Actor’s Take on Moviemaking, 2nd ed. (1997), 99.
Michael Caine discusses how he got the part and prepared for this role in a recent interview on NPR online.
In another interview on the Telegraph, Caine relates his reaction to hearing himself when Zulu was released.