At the center of Blue Bloods as a whole is the importance of family. Led by patriarch Frank Reagan (Tom Selleck), who works as the Police Commissioner for the NYPD, he obviously played a role in influencing his children to pursue careers in law enforcement as well. Throughout the show’s 11 seasons, their story lines have all intersected in intriguing ways when they’re out in the line of duty, but they all still make time to come together every Sunday evening to enjoy dinner as a family.

Those familial connections have paid off in big ways for the litany of characters on the police procedural as they’ve all gone through their fair share of hardships where they need people to lean onto. Both Frank and Danny (Donnie Wahlberg) are widowers, and Erin (Bridget Moynahan) is divorced from her ex-husband and ended up needing to raise her daughter Nicky (Sami Gayle) mostly on her own. Fortunately, with a big Irish-Catholic family, they’re all willing to lend a hand when necessary.

With such heavy themes connected to family, it only makes sense that it would also extend into the casting as well. Some Blue Bloods fans may have never realized that two primary cast members are actually related in real life.

The actors who play Danny’s sons, Sean and Jack, are brothers in real life

Danny had two children with his wife before she passed away — Sean (Andrew Terraciano) and Jack (Tony Terraciano). Those same last names aren’t just a coincidence; they’re actually brothers in real life too. They were cast on the series in the very first season when they were 6 and 8 years old, respectively. Their characters were those same ages when they were initially introduced, and audiences have been able to watch them grow up over the course of the last decade.

At the center of Blue Bloods as a whole is the importance of family. Led by patriarch Frank Reagan (Tom Selleck), who works as the Police Commissioner for the NYPD, he obviously played a role in influencing his children to pursue careers in law enforcement as well. Throughout the show’s 11 seasons, their story lines have all intersected in intriguing ways when they’re out in the line of duty, but they all still make time to come together every Sunday evening to enjoy dinner as a family.

Those familial connections have paid off in big ways for the litany of characters on the police procedural as they’ve all gone through their fair share of hardships where they need people to lean onto. Both Frank and Danny (Donnie Wahlberg) are widowers, and Erin (Bridget Moynahan) is divorced from her ex-husband and ended up needing to raise her daughter Nicky (Sami Gayle) mostly on her own. Fortunately, with a big Irish-Catholic family, they’re all willing to lend a hand when necessary.

With such heavy themes connected to family, it only makes sense that it would also extend into the casting as well. Some Blue Bloods fans may have never realized that two primary cast members are actually related in real life.

The actors who play Danny’s sons, Sean and Jack, are brothers in real life

Danny had two children with his wife before she passed away — Sean (Andrew Terraciano) and Jack (Tony Terraciano). Those same last names aren’t just a coincidence; they’re actually brothers in real life too. They were cast on the series in the very first season when they were 6 and 8 years old, respectively. Their characters were those same ages when they were initially introduced, and audiences have been able to watch them grow up over the course of the last decade.