Dean Stockwell was considered for the part of Joe Butler.
John Garfield would go on to do another 'Ernest Hemingway' (v) adaptation that year, The Breaking Point.
Otto Lang directed the European sequences, uncredited.
José Ferrer, Clifton Webb and Sydney Greenstreet were all considered for the role ultimately played by Luther Adler.
Although much footage was shot in Europe, the principle stars remained in California.
Production shut down for three weeks after John Garfield suffered a heart attack.
This was South African Noel Drayton's first film. Hired for his riding ability, he reportedly was an acquaintance of Fox studio chief Darryl F. Zanuck and went on to a successful 25-year career in films and television.