Don Draper (Jon Hamm) • The brilliant creative director and founding partner of Sterling Cooper Draper Pryce is mysterious and fascinatingly complicated.

Peggy Olson (Elisabeth Moss) • The secretary turned copy writer embodies, for both better and worse, the changes women confronted in the 1960s.

Roger Sterling (John Slattery) • The Sterling of Sterling Cooper bolted his old firm to partner with Don. But his marriage to a younger woman could be his biggest test.

Bertram Cooper (Robert Morse) • The Cooper of Sterling Cooper approved the merger with the Brits but joined the new firm when he feared being forced out.

Pete Campbell (Vincent Kartheiser) • The ambitious young accounts manager wants to be Don Draper but makes the wrong move at every turn, even in his marriage.

Joan Harris (Christina Hendricks) • The Sterling Cooper office manager married a doctor but couldn't admit her disappointment until the new firm called for help.

Lane Pryce (Jared Harris) • The Londoner came to New York with Sterling Cooper's British bosses but found himself on the outs and defected to the other side.

Betty Draper (January Jones) • The former model never shed her icy reserve to embrace the role of wife and mother. Don's lies pushed her to move on to a new life.

Henry Francis (Christopher Stanley) • The reserved Republican fell head over heels for Betty and took on her problems, and her three children.

Kiernan Shipka (Sally Draper) • Don and Betty's young daughter is increasingly troubled; her behavior often seems dangerous.

Harry Crane (Rich Sommer) • He led Sterling Cooper successfully into television and joined the new firm as head of media, but he still frequently feels inferior.

Paul Gladis (Michael Kinsey) • Copy writer has pretensions to being a serious author, complete with pipe. Wasn't recruited to the new agency.

Ken Cosgrove (Aaron Staton) • Competed with Pete for the job as head of accounts and won. Also not one of the founding members of the new agency.

Sal Romano (Bryan Batt) • Art director fired for refusing a client's sexual advances. Can't join the new firm because the same client is pivotal to the new agency.

By Gail Pennington