Grey's Anatomy has been a staple of American television since it first debuted on March 27, 2005. The series has run continuously for more than 14 seasons and shows no signs of slowing down anytime soon.

From the very beginning of the series, two characters stood out: Dr. Meredith Grey and Dr. Derek Shepherd. Sure, the series is all about Grey (it's in the name after all), but since the very first episode, it was clear that their relationship was going to go the distance. Sure, it had its bumps along the way, but what relationship doesn't? Even with some trials and tribulations, it was clear that Meredith and Derek were meant to be together.

Sadly, Derek passed away in 2015 when Patrick Dempsey and Shonda Rhimes (the series creator) came to an agreement to write the character off. Dempsey left the series for personal reasons and it came at a cost to Meredith - and to fans who had grown accustomed to watching the couple on screen for so many years.

Now that Derek is gone and Meredith has begun to somehow pick up the pieces of her life and move forward, we thought it would be fun to look back on the relationship many fans looked on with envy for more than a decade.

Test your knowledge with these 15 Things Only True Fans Know About Meredith And Derek’s Relationship.

15. THE WAY IT ALL BEGAN

Derek and Meredith Meet on Grey's Anatomy

If you think all the way back to the beginning, Derek and Meredith's relationship began in a somewhat unconventional way.

The pair met up at Joe's without knowing who or what the other did. Pretty much the usual way folks meet these days for a one-night stand, but in their case, things got a little complicated. After concluding their evening without making any attempt to see the other again, they head off to their respective jobs. Derek made his way to work as the chief of Neurology at Seattle Grace while Meredith went in for her very first day on the job.

This wouldn't normally be a big deal except for the simple fact that Meredith was beginning work as an intern at the same hospital. Awkward!

Not only did she romance with someone she was about to begin a professional relationship with, he happened to be one of her bosses. Shonda gave us all the fun and excitement of a new relationship amidst the crushing reality that you really shouldn't sleep with your boss.

Looking back at Derek and Meredith's relationship as a whole, it's fun to see how it all began in much the same way many people get together.

14. DEREK'S SECRET MARRIAGE

Dr Addison Montgomery from Grey's Anatomy

Derek and Meredith's relationship began in an unconventional and messy way, but it was much more of a problem than we were led to believe in the beginning.

Unbeknownst to just about everyone at the hospital and the viewers alike, Derek was married when he met Meredith in the bar. He remained married as their relationship began to develop and in pure Shondaland fashion, just as the two were falling in love and everything began to look perfect for Meredith and the man she loved, in walks his wife!

Dr. Addison Adrianne Forbes Montgomery, formerly Montgomery-Shepherd, was presented as a world-class neonatal surgeon - and nothing but pure competition for Meredith.

Not only did Meredith suddenly have to contend with the fact that Derek had a wife and was still legally married, but she was beautiful, knew all about Derek's past - which was something the show kept closely guarded at this point - and she was an incredibly talented physician.

Later, we all learned that Dr. Montgomery was brought onto the series to help launch the show's first spinoff, Private Practice, but that was still a few seasons in the future. It was interesting to delve into Derek's past, but Meredith was put into a tough position when Addison strolled into the hospital.

13. DEREK ALMOST LOST MEREDITH BY TRYING TO SAVE HIS FIRST MARRIAGE

Derek Shepard and Addison Montgomery on Grey's Anatomy

Addison popped into the hospital unannounced in the ninth episode of the first season and Derek was presented with a choice. Should he continue to develop the amazing relationship he was building with Meredith or should he end things with the young intern and see if he could rebuild his damaged marriage?

Their union had taken a hit thanks to a brief fling of infidelity between Addison and the pair's best friend, Dr. Mark Sloan. Derek weighed his options and opted to return to Addison. Tthe rejection was a crushing blow to Meredith who spent quite a few episodes getting over Derek.

When Derek decided to try and mend his relationship with Addison, Meredith didn't take it very well.

The rejection made it so Meredith could no longer trust Derek, and their professional relationship didn't advance on the best terms in the early seasons of the series. Whenever the two got stuck traveling in an elevator again, the tension and angst were palpable.

We all know that the pair finally got back together in the end, but the problems that arose from the initial rejection created a rift between the characters, which - at the time - made it seem they would never get together again.

12. THEIR ON-AGAIN/OFF-AGAIN HABITS

Meredith Grey and Derek Shepherd Greys Anatomy in an elevator

Looking back at their relationship, it might be hard to remember that the pair who seemed destined to be together had such a rocky relationship at the beginning.

When they first got together, Derek and Meredith were simply casual, but it started to develop into something more. Just as they were getting to a good point in their relationship, Derek's wife came back and he broke things off with Meredith to try and make things work. That may have been the first time this pair broke up their relationship, but it would not be the last.

Calling their first few seasons/years "rocky" would probably be an understatement.

It took several seasons before they were finally together thanks to various problems arising between the two. Just when you thought things were going well, Rhimes would throw something at them like a shooting or something really nasty, like another guy.

Even when they were finally together, they still ended up apart for long periods of time. Derek had to move to Washington, D.C. for work at one point, which strained their marriage, but he eventually returned to Seattle not wanting to be away from his family anymore.

11. A DOG KEPT THEM FROM GETTING BACK TOGETHER

Meredith Grey and her dog Grey's Anatomy

To be clear, sharing a dog isn't the biggest thing we could have written about here, but it's what happened thanks to the dog that lands this entry on the list.

Just after Derek returns to Addison, Meredith decides to adopt a dog. Eventually, she and Derek share the dog, but before that can happen, the dog played a large part in keeping them from getting back together. This happened thanks to the rather attractive young veterinarian Meredith took the dog to visit.

Veterinarian Finn Dandridge, played by Chris O'Donnell, begins to date Meredith in the second season and does so for some time.

The pair are together, and appear to be as serious a couple as you can get throughout the end of the second season and into the third. It looks as if Meredith may have finally found her one, but she ends up breaking up with Finn when she can no longer deny the fact that she is still in love with Derek, who has finally bailed on the prospect of keeping his marriage afloat.

Finn was a great guy, but Meredith admits that he wasn't "her guy" and he ends up leaving forever when she returns to Derek.

10. THEIR CAREERS SUFFERED FOR THEIR RELATIONSHIP - AND VICE-VERSA

Derek Shepherd and Meredith Grey Grey's Anatomy

If you look at their overall careers, they haven't suffered very much. If you're all caught up on the series, you already know that Meredith has won a Harper Avery Award, which is pretty much the gold-standard of medical awards presented throughout the first 11 seasons of the series.

Derek was at the top of his game throughout the series, so you might be scratching your head wondering what is going on here. For Meredith, her career could have gone much differently had she made better choices.

She made a series of errors in judgment when they were working on a medical trial, which resulted in the complete destruction of the trial, and damaged both their reputations.

This didn't help either of their careers, but if you shoot a bit further into the future and look at Derek, he was all set to work directly under the President of the United States on a program in Washington, D.C. He took the job and moved there, but the problems this caused in his and Meredith's relationship ultimately forced him to return.

He ended up giving up the best possible job he could have taken for the sake of his family. It's not that we can blame him for making the decision, but their relationship has definitely had an impact on both of their careers.

9. MEREDITH'S FIRST TRAGEDY

Meredith cries in Grey's Anatomy

It wouldn't be a Shonda Rhimes show without some serious drama and if you look at Meredith's life, drama is certainly her go-to.

After a patient is taken off life support, her husband is racked with guilt. Instead of handling this in a healthy way, he decides to make the people he considers responsible pay with their lives. The man, Gary Clark, then goes on a shooting rampage through the halls and floors of the hospital. He first takes out a young intern and then shoots Alex Karev in the chest when he comes upon the scene. Numerous people are hurt and killed in the ordeal until it seems to finally come to an abrupt end.

As Derek walks upon the scene, he is immediately shot and nearly loses his life. In the operating room, Clark tries to stop Christina from saving his life and threatens to end her, but Meredith offers herself in his place. When Christina tells him Meredith is pregnant, he hesitates. Owen is shot in the struggle and things go from bad to so bad, we don't have an adjective for it. The strain on her resulted in Meredith losing what would have been the couple's first child.

8. THEY GAVE AWAY THEIR WEDDING

Izzie Stevens and Alex Karev Grey's Anatomy

It took a long time for Derek and Meredith to finally come to the point where they were ready to get married. The couple suffered a great deal of adversity along the way so when it finally came time for them to tie the knot, it looked like nothing could stop them - except for a little more adversity, of course!

This time, it wasn't centered on them but rather, two of their best friends. Izzy Stevens and Alex Karev were also getting to the point of tying the knot after a long period of relationship instability when Izzie's illness started to worsen. Izzie had been helping Meredith plan her wedding from her hospital bed, even going so far as to create a website for them.

Unfortunately, Izzie's condition worsened and it became necessary to perform a risky operation to remove a new tumor found in her brain - which was causing her to see Denny, the man she fell in love with prior to Alex.

Because of the risk involved with the surgery and the possibility that Izzie might not survive, Meredith and Derek gifted their planned wedding to Alex and Izzie, who gratefully accepted.

It was yet another setback for Meredith and Derek, but they didn't let it keep them from marrying for long.

7. THEIR UNCONVENTIONAL WEDDING

Meredith signs the post-it note

When a couple has been together for as long as Derek and Meredith, or had been on-again/off-again for as long as them, it may seem like they will never get married. Even after they had a wedding planned, they ended up just giving it away to their friends so it didn't look great for their ever tying the knot.

Fortunately, they finally did make their vows, but not in what could ever be considered a traditional ceremony. If you think about what a wedding is, it's a ceremony that places two people across from one another where they make certain promises to one another in the form of vows. It's all beautiful, fun, and romantic, but it isn't legal - until they sign the state-mandated marriage license.

That's the document the state needs to find a couple "legally married" and, without it, it can become difficult to do things like insuring one another or open a bank account. For Meredith and Derek, they decided to skip all of that and simply write down their vows on a standard-issue Post-It Note, found in any office in the world.

As far as they were concerned, from that point forward, they were married and nobody in the world could tell them otherwise. They framed the Post-It Note and that was all they needed to call each other husband and wife.

6. THE POST-IT

Greys Anatomy Post-It Note

After Derek and Meredith finally got married via their Post-It Note, the note itself became incredibly significant in a way that no married couple ever refers to their marriage license.

Whenever they would fight or have a serious issue with one another, which happened fairly often for a couple as in love as they were, they would call "Post-It" and that would effectively stop the argument.

Calling "Post-It" made the other person recall what was written on their note, especially the first part, which was, "Love each other even when we hate each other." Granted, this was followed by "No running," but it helped both of them remember what they meant to one another, even if they were angry.

Reading the rest of the note, you can see it says that they will "Take care when old senile and smelly and it's forever." The two signed it and that was what they based their marriage upon. Even until the very end, they both relied on the note whenever they were fighting. When Derek moved away for a job in D.C., the note became an even more significant aspect of their relationship. In a lot of ways, the Post-It Note was the physical embodiment of their marriage.

5. MEREDITH ONCE LEFT DEREK IN JAIL

Meredith Grey leaves Derek Shepherd behind bars Grey's Anatomy

After Derek was shot, he doesn't do what a lot of people might, which is avoid danger. Instead, he begins to show increased disregard for his own safety in what can only be described as a search for more adrenaline in his life.

At this point in their relationship, Derek and Meredith are married via Post-It Note and they are about as serious a couple as they can be, but Meredith is constantly worried about him. His behavior is so destructive, she doesn't know how to handle it and when it lands him in police lock-up, she has two options: she can bail him out or let him stay in the cell for the evening.

Meredith opts to keep Derek in jail for the simple fact that she will know where he is, he is safe, and isn't "wrapped around a telephone pole somewhere."

Having his wife leaves him in jail overnight certainly didn't make Derek happy, but it did serve as a wake-up call for him. It took a little time and effort, but he managed to return his life to a normal level of adrenaline, which was good because he had nearly driven Meredith crazy trying to deal with him during this time.

4. THEY OFFICIALLY GOT MARRIED SO THEY COULD ADOPT

Derek and Meredith get legally married Grey's Anatomy

We already mentioned how their marriage wasn't exactly legit under the watchful eyes of the law. For the most part, this wasn't a big problem for the couple in their jobs or their personal lives. Their friends respected their rather unorthodox "wedding" and they certainly didn't have any problems at work, but there came a time when they decided it would be a good idea to really get married.

A requirement to trot on over to City Hall and make their marriage official arose when it came time to adopt their first child, Zola.

Zola had been a patient at the hospital who was flown to the States for treatment in a program at the hospital. Meredith and Derek fell in love with the little girl and decided to adopt her, but without a legal marriage, the State wouldn't entertain the idea. They decided to marry at City Hall, which was shown in a shot-for-shot comparison to the wedding of Arizona and Callie, who were knocking out the more traditional nuptials across town at the same time.

With their marriage finally certified by the government via a judge, the couple were able to move forward with the adoption of Zola.

3. Derek Bailey and Ellis

Meredith Grey and her three children Grey's Anatomy

We already discussed how Derek and Meredith came together to adopt Zola, but they also had two children of their own before Derek passed away.

Their first child together, Derek Bailey Shepherd who entered the world in a dramatic way - as you might expect on this series. Derek Bailey was born during a superstorm, which presented its own serious concerns, but that wasn't enough for Grey's Anatomy: he was also born in face-up presentation, which required an emergency c-section in the dark thanks to the storm having knocked out the power. Meredith almost lost her life shortly after thanks to a hemorrhage suffered at that time, but Dr. Bailey saved her.

Their second child, Ellis Shepherd, wasn't born until after Derek's passing. She was likely conceived the day before he lost his life. After he passed, Meredith took her other children and left Seattle with only a single note to her friends and family, which read, "The kids and I are safe."

Meredith suffered a placental abruption during delivery, but Ellis entered the world safely and the family returned to their home in Seattle. The children don't make many appearances on the show other than a few scenes involving dropping them off at daycare, but their roles may increase as they get older.

2. THEY HAVE SAVED EACH OTHER'S LIVES

Derek Shepherd Saved Meredith Grey Grey's Anatomy

Throughout the series, there have been multiple incidents where characters have either come close to losing their lives or have actually passed on.

While it's true that Derek is gone from the series, he had a near-loss experience when he was shot, as we previously mentioned. Due to their relationship and the extent of his injuries, it fell to Dr. Christina Yang to try and save his life, which she was trying to do when the gunman came in and tried to stop her. It was Meredith who stepped in the way and offered her life in exchange. This ultimately enabled Christina to continue working on her patient, which saved his life.

For Meredith, she has nearly perished a couple of times on the show. In a season 12 episode, she was nearly beaten by a patient, but she survived. In another incident, she was nearly blown to bits when an explosive device she handled for most of the episode finally detonated just after she passed it off to an ordinance disposal specialist. She nearly succumbed to that, but back in season three, she nearly drowned offshore while working on a ferry disaster. It was up Derek to fish her out of the water and get her the urgent medical care she needed to survive.

1. DEREK WILL ALWAYS BE MEREDITH'S "ONE"

Meredith Grey and Derek Shepherd Greys Anatomy

Derek passed away at the end of the 11th season of the show. He lost his life following a vehicle accident after he was able to save some other people injured in the same location. The loss was absolutely devastating, not only to Meredith Grey and the characters on the series but to the fans as well!

Meredith and Derek's relationship was the driving force of show from the first episode. While lots of other characters came and went with their own relationships, problems and triumphs, Grey's Anatomy is all about Meredith and her one true love: Derek Shepherd.

It seemed unlikely Meredith would ever recover from her loss, but if this woman is capable of anything, it's surviving what would have destroyed pretty much any other person on the planet.

While she has engaged in relationships post-Derek, none have measured up to her "one" and she still uses Derek as a measuring stick from which to compare every person she even considers beginning a romantic relationship with. If the show were to shoot forward 30 years into the future, it would be highly unlikely to follow the adventures of a Dr. Meredith Grey who wasn't still deeply in love with Dr. Derek Shepherd.

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Do you have other MerDer knowledge to share from Grey's Anatomy? Let us know in the comments!