Christopher Pike served as captain of the U.S.S. Enterprise along with officer Spock for over 11 years prior to James T. Kirk taking command. The new Star Trek film is now set to occur during that time while most of the future bridge crew is still in Starfleet Academy.
Canadian actor Bruce Greenwood will play Captain Pike, having appeared previously as Mitch Yost on John from Cincinnati and in films such as Eight Below, Capote, Racing Stripes and I, Robot.
Source: Hollywood Reporter