The relationship between the humans, John Gilbert and Alaric Saltzman. The two became rivals from the first time they met, as they were both previously in love with Isobel Flemming, and they were both Vampire Hunters. They both had guardian-esque relationships with Elena and Jeremy Gilbert as well.
Throughout the Vampire Diaries Series
Alaric first met John in Under Control during the Founders' Day Kick-Off Party. After John antagonized Damon, Damon threw him off of the Lockwood's balcony and he died, only to be resurrected shortly afterward. Damon noticed that he wore the same ring as Alaric, which previously brought Alaric back to life after Damon had killed him. When Damon brought this up, Alaric informed him that he got his ring from Isobel, and asked Damon if he thought John knew Isobel as well. Later that night, Damon and Alaric confronted John, and Alaric asked him where he got his ring. John revealed that the ring he was wearing at the time he inherited from his brother Grayson, but that he gave his original ring to Isobel. He then added that had he known Isobel was just going to give it another guy, he would have reconsidered gifting it to her in the first place.
In Blood Brothers, Alaric and Damon tried to find the Gilbert Device before John could, and got the device from Pearl. However, when Isobel threatened to kill innocent Mystic Falls residents, including Jeremy, they were forced to hand the device over to her, and she gave it back to John.
In Founder's Day, John activated the Gilbert Device and rounded up all the vampires. Alaric noticed this, and tried to thwart part of John's plan to kill all the Mystic Falls vampires by helping rescue Stefan and Damon so they wouldn't be killed in the round-up.
John made his return in Daddy Issues and unsuccessfully tried to convince Alaric to give him his ring back. He also started working on ruining Alaric's relationship with Jenna by dropping hints that Alaric was hiding things about his relationship with Isobel from her.
In Crying Wolf, John tried to blackmail Alaric by telling Jenna that Alaric wasn't trustworthy and he wasn't being truthful about Isobel's death. Alaric ultimately ended up giving John his ring back, and John sent Isobel to the Gilbert House, thereby revealing to Jenna that Alaric had been lying to her and contributing to Alaric and Jenna's temporary breakup.
- They first met in Under Control during the Founder's Day Kick-Off Party.
- They both had a romantic relationship with Isobel.
- Isobel is the mother of John's daughter Elena.
- Isobel was Alaric's wife before she left him after being turned into a vampire by Damon. This technically made Alaric the step-father to Elena.
- Both of them have dated Jenna at one time.
- In Daddy Issues, John tried to convince Alaric to give him his ring back.
- In Crying Wolf, John tries to blackmail Alaric by telling Jenna that Alaric wasn't trustworthy and wasn't being completely honest about the circumstances surrounding Isobel's death.
- They were both killed by Damon (and revived with the Gilbert rings).
- They both watched over and wanted to protect Elena.
- They were both vampire hunters at one time.
- They both were the owner of Gilbert rings.
- Both of their deaths were connected to Elena and a spell cast by a witch.
- John had Bonnie link his life-force to Elena in The Sun Also Rises so that when she died in the sacrifice, she would come back to life.
- Esther linked Alaric's life to Elena's after she turned him into an Enhanced Original Vampire, to ensure he would only live one human life time, as opposed to the immortal Original Vampires. Rebekah ran Matt and Elena off Wickery Bridge, drowning Elena, which therefore killed Alaric. However, Alaric was resurrected in Home.