Allen Leech (born 18 May 1981), known in his early career as Alan Leech, is an Irish stage, television and film actor. A native of Killiney, Leech made his professional acting debut with a small part in a 1998 production of A Streetcar Named Desire. He made his first major film appearance in as Vincent Cusack in Cowboys & Angels and earned an Irish Film & Television Awards nomination in 2004 with his performance as Mo Chara in Man About Dog. Leech came to international attention as Marcus Agrippa on the HBO historical drama Rome and is best known for his role as Tom Branson on the internationally successful costume drama Downton Abbey.