Professor Snape's first movie was Die Hard. He was 41!

The famed British actor Alan Rickman had never done any film acting before his big role in Die Hard as Hans Gruber. This fact probably results from the fact that Rickman prefers acting in plays. 

Nevertheless, his performance in Die Hard was so incredible that his character made it into number 17 of the 100 greatest movie characters. Rickman acts out a super smooth villain with a witty tongue. 

He turns Gruber into a somewhat ambiguous villain, a villain that the viewer almost wants to root for. His ability to create such 3-demensional villains is something Rickman is also famed for in his role as Snape in the Harry Potter movies. 

His role as Snape has earned him the undying affection of many Harry Potter fans. Nevertheless, Rickman is not just a man in black robes. As Gruber, he is a brilliant thief, and one of his best moments in the movie is opening up the Nakatomi vaults, basked in the light of success. 

He is also known for his roles in Sweeney Todd, Sheriff of Nottingham, Sense and Sensibility, and many others. He has been nominated and won many awards for his acting abilities. 

(Source)