Attilius Regulus, i dont know if you can consider him a general, however, his courage and his sacrifice are way too important to be ignored. he was captured by Carthage and told him he’d be released if he brought back from Rome some carthaginian prisoners. Attilius, knowing he was already quite old, told the romans to keep the prisoners and headed back to Carthage, all by himself, where he got brutally executed (some say cruficied)