It’s not just the ensemble of Chicago Fire that has changed over the last 12 seasons as old

cast members exited and new ones joined the fray. The NBC drama’s characters, too, have

evolved over the years in their job titles, marital statuses and personal arcs. Below,

TVLine is looking back at how the most recent crop of firefighters and paramedics has grown, from personality traits to major life changes, in the time from their first episodes (pictured on the left below) to now (pictured right below). And considering how long the hit #OneChicago show has been on the air, it’s no surprise that there have been some big transformations. But first, some notes about who’s included and who’s not: In addition to the current cast, we’ve selected a couple of characters who made return appearances last season to offer viewers an update on their lives (Casey) or who only recently exited the series (Brett, Boden).

Not featured are all those whom we loved and lost, but you can relive their tragic deaths here. And since we haven’t gotten an update on Gabby Dawson in a long time, we’re just going to assume that she’s still rocking the medical aid work. Check out the list below to review the firehouse crew’s character evolutions, then hit the comments to tell us who you think has evolved the most from their debut! It’s not just the ensemble of Chicago Fire that has changed over the last 12 seasons as old cast members exited and new ones joined the fray. The NBC drama’s characters, too, have evolved over the years in their job titles, marital statuses and personal arcs. Below, TVLine is looking back at how the most recent crop of firefighters and paramedics has grown, from personality traits to major life changes, in the time from their first episodes (pictured on the left below) to now (pictured right below).

And considering how long the hit #OneChicago show has been on the air, it’s no surprise that there have been some big transformations. But first, some notes about who’s included and who’s not: In addition to the current cast, we’ve selected a couple of characters who made return appearances last season to offer viewers an update on their lives (Casey) or who only recently exited the series (Brett, Boden). Not featured are all those whom we loved and lost, but you can relive their tragic deaths here. And since we haven’t gotten an update on Gabby Dawson in a long time, we’re just going to assume that she’s still rocking the medical aid work. Check out the list below to review the firehouse crew’s character evolutions, then hit the comments to tell us who you think has evolved the most from their debut!

Christopher Herrmann (Played by David Eigenberg) Herrmann may sometimes come off as a grouch, but the seasons have revealed the soft heart underneath that exterior. From his devotion to his wife and their five kids during her cancer battle and to the way he looks out for the firehouse’s newbies, Herrmann has emerged as a surprisingly stable and open-hearted source of support at 51, which is why Boden suggested Herrmann as his replacement for chief. As a CFD veteran, Herrmann is facing the challenges of age and injury on the job with his partial hearing loss, but he also proves that the best is yet to come with time.

Darren Ritter (Played by Daniel Kyri) As a newbie firefighter, Ritter had a lot to learn: He froze during a crucial call, but Mouch saw something in him, and Ritter was recruited to Firehouse 51. Under Mouch and Herrmann’s mentorship, he’s evolved into not only a capable firefighter, but also someone who is comfortable enough to come out to his colleagues — he’s now dating a cop — and someone who can always be relied upon for a caring and thoughtful ear. Joe Cruz (Played by Joe Miñoso) The teddy bear of the firehouse crew, Cruz’s heart has only grown bigger as a married man with a baby boy and an adopted son. While he may be a softie with his loved ones, Cruz has become more assertive at work and found new self-confidence, moving up the ranks to rescue squad, where he served as acting lieutenant and even stood up to Severide. Kelly Severide (Played by Taylor Kinney)

As a former ladies’ man, Severide has perhaps come the longest way of any Fire character from his early days of short-lived relationships and flings with Renee, Brittany, Anna and Erin Lindsay, just to name a few. He found his match in wife Stella Kidd and even recently declared that he wants to start a family. How times have changed! And remember how tense things were between Severide and Casey in Season 1, following Andy Darden’s death? Well, that friendship has blossomed into something so strong that Severide was the Best Man at Casey’s wedding. The loss of his best friend Shay also played a big role in Severide’s evolution, sending him on emotional spiral (and toward a quickie marriage with Brittany), but ultimately, helping him to mature.

Meanwhile, at work, the rescue squad lieutenant has developed a knack for fire investigation, much like his late father Benny. Matt Casey (Played by Jesse Spencer) Life sure looks different for Casey now compared to Season 1. From the very start of the series, the firefighter has always wanted to be a married family man, but his engagement to Hallie ended when she was tragically caught in a fire at her place of work. Then Casey’s marriage to Gabby Dawson abruptly fell apart when she decided to take a job as an medical aid worker in Puerto Rico. (Before that, Casey briefly got to be a father when he and Gabby temporarily fostered little Louie.) The lieutenant-turned-captain’s dream did finally come true as he married Sylvie Brett and moved with her (and her adopted daughter) to Portland, Oregon, where the couple are currently raising the late Andy Darden’s sons. Stella Kidd (Played by Miranda Rae Mayo) When a divorced Stella joined the firehouse, she was already old friends with Gabby Dawson and shared a history with Kelly Severide, who once broke into her house with booze, not realizing she was married at the time.

But little did she know that her would-be evening with Severide would eventually lead to her getting the playboy to finally settle down. (Thank goodness she ditched her troubled ex Grant!) And marriage isn’t the only accomplishment on Stella’s record: Seeing a void in the CFD, the firefighter started a Girls on Fire mentorship program and moved up the ranks to serve as lieutenant of Truck 81 with commanding grace. Sylvie Brett (Played by Kara Killmer) When the paramedic first joined the firehouse, she was a somewhat meek and naïve suburban gal trying to adjust to the big city. Brett even took a backseat in her relationships, with a controlling ex-fiancé from back home, and then another ex-fiancé, Kyle, with whom she moved to her small hometown even thought it was no longer the life she wanted. Eventually, Brett embraced her power and independence, thriving at work, where she became the Paramedic-in-Charge and launched a successful paramedicine program, while also marrying the love of her life, Casey.

The couple now reside with their kids in Portland, Oregon. Violet Mikami (Played by Hanako Greensmith) Initially introduced as a temporary replacement on Ambulance 61, Violet has now been promoted to Paramedic-in-Charge following Brett’s exit. She’s also come a long way in her personal life, from her on-and-off relationship with firefighter Blake Gallo to her tragic love story with the late Paramedic Field Chief Evan Hawkins to her current attempt at a no-strings-attached dalliance with firefighter Sam Carver. Given everything that life has thrown at her recently, including have to say goodbye to her best friend Brett when she moved across the country, it’s no surprise that Violet’s spunk and competitiveness has somewhat mellowed from her debut, but in a way that’s only deepened the character.