General Madine is one of the most interesting characters that barely got any screen time in the original films. He was a member of the Rebel Alliance who stole plans from the Empire and, as a former Imperial officer who defected after being ordered to commit genocide, was instrumental in the destruction of the second Death Star. Also, he was the one who convinced Mon Mothma of the necessity of killing Emperor Palpatine - it's difficult to know what would have happened had the emperor survived the battle. After the Rebel Alliance won the war, he continued his work with the military, embarking on a number of dangerous, top secret missions. Although he isn't the most recognizable character in the franchise, he was a key member of the Rebel forces and stands a decent chance of showing up again.