Brenan Gleeson has a very large and impressive filmography. His résumé includes such films as Cold Mountain (2003), Gangs of New York (2002), A.I. (2001), 28 Days Later (2002), and Mission Impossible 2 (2002), as well as many many others. While that is farily impressive, what may be more impressive is he only started acting professionally at the age of 38! Source