Blue Bloods got viewers invested in the Reagan family - but how are the characters related to each other? The CBS series, which premiered in 2010, followed the lives of the Reagan family, many of whom worked for the NYPD under the leadership of NYC police commissioner Frank Reagan (Tom Selleck). Frank's father, Henry Reagan (Len Cariou), was also central to the show alongside Frank's children: daughter Erin Reagan (Bridget Moynahan) and sons Danny (Donnie Wahlberg) and Jamie Reagan (Will Estes).