A talented doctor who liked to surf and had a passion for saving the planet, Dr. Daniel Jonas was instrumental in getting a hospital in Switzerland to "go green."

The early history of Daniel Jonas was not shown on screen, but told through stories. Before coming to Salem, Daniel worked as a doctor for various hospitals around the world. While working at one hospital, he met and fell in love with a cancer patient named Rebecca. Although he knew that her diagnosis was grim, Daniel married Rebecca and was determined to save her. However, her cancer was too much and she died in Daniel's arms. Since her death, Daniel traveled the world, not staying in any place for too long.

In March 2008, Victor brought his godson, Dr. Daniel Jonas, to Salem to help diagnose and treat Bo's mysterious pancreas disease. Daniel saved Bo's life by performing a live donor transplant. In this case, the live donor was Bo's daughter, Chelsea. After the successful surgery, Lexie offered Daniel a permanent job with Salem University Hospital, and he accepted.

Despite their age difference, Chelsea quickly began to take a romantic interest in Daniel. But, Daniel was not interested in a relationship-- with Chelsea or anyone else-- due to his experience with Rebecca. However, Daniel found it hard to ignore his feelings for Chelsea. Soon, he gave in and the two started dating.

Bo and the rest of the Bradys made peace with Daniel and Chelsea's age difference, when viewers learned that Daniel and Kate had a brief but passionate affair when Daniel was Chelsea's doctor. Daniel and Kate both maintained that Chelsea must never find out about them. But she did find out when she saw a text message from Kate on Daniel's phone. She dumped Daniel and was furious with Kate.

When Chelsea dumped him, Daniel picked up his flirtation with Kate. The two became close again, and even closer when Daniel diagnosed Kate with lung cancer. Daniel worked hard to cure Kate's cancer, even performing a radical bone marrow transplant with Chloe as the donor. As Kate began to heal, Daniel developed feelings for Chloe. Despite the fact that Chloe was engaged to Lucas, Daniel had fantasies about making love to Chloe. The two tried to fight off their attraction. When Kate broke things off with Daniel, he started pressuring Chloe to break things off with Lucas so that they could be together. At first, she refused, but on the day after her engagement party, Chloe and Daniel made love.

Daniel and Chloe couldn't stay away from each other, despite the fact that Chloe did go through with her marriage to Lucas. Kate caught Daniel and Chloe together in the park and was furious. She poisoned Chloe and set Daniel up to take the fall- complete with planted finger prints on the bottle of poison in Daniel's apartment. Chloe fell into a coma. Daniel was arrested for the crime.

Once out on bail, Daniel fought to save Chloe. He snuck into her hospital room to administer a life saving drug. When Chloe woke up, she confirmed Daniel's story that the two of them were in love and the charges against Daniel were dropped. Daniel and Chloe got engaged and prepared to start a family.

Little did Daniel know that he already had family in Salem - a daughter. Carly returned to Salem in the fall of 2009 with a secret, which soon came out. Thanks to a one-night stand, Daniel was Melanie Layton's biological father. When the news came out, Daniel set out to get to know his new daughter.

While Daniel and Melanie built a relationship, Daniel's relationship with Chloe ran into trouble. Mistakenly thinking that Daniel was sleeping with Carly, Chloe had a one night stand with Philip. To complicate matters, a few weeks later Chloe found out that she was pregnant. Daniel was thrilled. Chloe worried that the baby might not be Daniel's. So, she got a paternity test. The results showed Daniel to be the baby's father.

Never knowing that the baby might not be his, Daniel pushed forward with the wedding plans. Daniel and a pregnant Chloe were married in the park on October 14, 2010. A few weeks later Chloe gave birth and Daniel was thrilled to spend time with his new son, Parker. But their happiness was short lived. On the day of Parker's baptism, Caroline Brady confessed that she had switched the paternity test results and Philip was really Parker's father. Devastated, Daniel divorced Chloe and tried to move on with his life.

Daniel met Jennifer while working at the hospital and the two began casually dating. Both knowing that they had come fresh of divorces, they wanted to take things slow. But Daniel soon found himself very happy with Jennifer and wanted to move things along. Jennifer returned his feelings and the two began happily dating.

One night while Jennifer and Daniel were away for the weekend at a spa, Melanie called Daniel and asked him for the code to the free clinic outside of town. Worried that she was in some kind of danger, Daniel and Jennifer rushed to the clinic. There, they found Melanie trying to save a badly beaten E.J. Daniel jumped in and started performing surgery to stop the internal bleeding. Jennifer went to get Carly to help with the surgery. Once E.J. was stable, Daniel took him to Salem U Hospital. To protect everyone involved (including Brady, who was the one who beat E.J.) Daniel told Lexie that he had found E.J. on the pier and, alone, performed all surgeries to stabilize E.J.

To make up for the spa weekend that they had to cut short, Daniel invited Jennifer to go to San Francisco with him. Jennifer abruptly said no and broke up with him. Daniel had no idea that Jennifer was intentionally pushing him away because Jennifer learned that Carly had feelings for Daniel and was taking pills. Jennifer thought that if she gave up Daniel, Carly would stop abusing the drugs. Eventually, Jennifer came clean with Daniel about Carly's feelings, but did not tell him about the pills. Daniel went to talk to Carly to tell her that there was no chance that the two of them would be anything more than friends.

When a picture of a passed-out Carly surrounded by pills showed up online, Daniel went to find her. Daniel found Jennifer at Carly's hotel room. Jennifer confessed that she had known about the pills all along. Daniel was furious with Jennifer for keeping Carly's addiction a secret. While Daniel and Jennifer were arguing, Carly slipped out the bathroom window. Daniel, Jennifer, and Melanie began looking for her.

Their search was not successful. However, Quinn Hudson found Carly in an alley and helped her realize that she needed to return to the people who loved her and enter rehab. Daniel was thrilled when Carly came home safe. Happy that his friend was on her way to being healthy again, Daniel turned his attention back towards Jennifer.

On the night of the Horton Square dedication, Daniel asked Jennifer to move in with him. Just as he got the question out, Jack, Jennifer's ex-husband fell from the above balcony onto the cake that Jennifer and Daniel were standing next to. Suddenly, Jennifer had a big decision to make - Jack or Daniel. Both men agreed to give her some time to make her decision and both spend alternating days with Jennifer while she made up her mind.

At the same time, another woman entered Daniel's life. Bo and Hope found documentation at Alice's house, leading to the revelation that Daniel's parents had used an egg donor to conceive Daniel. However, it turned out that the eggs were actually stolen, and the eggs we're Maggie's. Daniel tried to process the idea that Maggie was his biological mother, despite his parents never saying anything to him about it. Quickly, he began to accept the idea of Maggie as his biological mother.

With his recently renewed sense of family, Daniel realized that Jennifer needed to give her family with Jack a fair shot. So, he went to Jennifer and told her that he would back off while she gave Jack a chance.

Around the same time, Daniel received some medical test results back. Because he and Melanie were both related to Maggie, they were tested for MG. Neither had the gene, but Daniel was still experiencing unexplained tremors. Lexie finally diagnose with intention tremors, probably caused by a small stroke he suffered in his sleep. The tremors were incurable, which meant that for the time being, he could no longer be a surgeon. This news, coupled with the grief over losing Jennifer, prompted Daniel to leave Salem for a bit to clear his head.

When Daniel returned to Salem, he decided to focus on being a doctor and officially broke things off with Jennifer. He wasn't single for long, as he soon became wrapped up in Nicole's scheme to keep her baby from E.J. Daniel knew that Nicole switched the paternity tests, but kept quiet about it. Shortly after, Daniel and Nicole started sleeping together. They both insisted that they were just "having fun." But, Daniel seemed to be developing feelings for Nicole. That is, until Jack died and he Daniel realized that his feelings for Jennifer never went away.

Nicole was furious and began scheming to keep Daniel and Jennifer apart. Daniel was honest with Nicole that he did not return her exact feelings, but he did agree to go away to Hawaii with her to start a new life. However, Nicole tragically miscarried just before she was to give birth. After she left the hospital, Nicole went to Daniel's apartment and heard Jennifer leaving a voicemail for Daniel to meet her in the town square. Nicole went instead and confronted Jennifer. Jennifer tried to walk away, but Nicole rushed after her. Nicole followed Jennifer up the stairs and grabbed Jennifer's arm. When Jennifer jerked her arm away, Nicole fell down the stairs. When people rushed to see if Nicole was okay, Nicole immediately said that Jennifer pushed her.

Nicole was rushed to the hospital where she delivered her baby. When Dr. Davis pronounced that the baby was dead, Nicole insisted that Jennifer was the one who killed the baby. Jennifer was arrested. But, Daniel was sure that Jennifer was innocent. So, Daniel offered Nicole a deal -- drop the charges against Jennifer and he would still move to Hawaii with Nicole. Nicole agreed and told the police that she misremembered the events of her fall and that her fall was an accident.

As Daniel was closing up some loose ends at the hospital, he came across an infant t-shirt in the lost and found that he recognized as part of a set that Nicole had purchased for her baby. Wondering why it was in an exam room, Daniel looked into Nicole's last doctor's appointment and learned that Nicole had actually miscarried the baby before the altercation with Jennifer on the stairs. Daniel confronted Nicole with the information. Rafe, E.J., Jennifer, Brady, and Abigail all witnessed it. Nicole cried and admitted that she had, in fact, made the whole thing up to keep Daniel from going back to Jennifer. Daniel told Nicole that they were not moving to Hawaii.

But, Daniel did not hold a grudge against Nicole. Instead he just focused on moving on with Jennifer. However, Chloe soon returned to town with the news that Parker actually was Daniel's biological child. Daniel was thrilled, but he didn't count on Chloe wanting him back as well. Chloe schemed to break Jennifer and Daniel up, despite his protests that he does not want to be with Chloe.

Finally, Chloe went to Jennifer and told her to give up Daniel, or Daniel would never see his son again. Jennifer tried to break up with Daniel, but he was sure that someone was forcing her to do so. He suspected Chloe, but he had no proof until he found Nancy's recently stamped passport in her purse. He called Rafe with the information, who made a few calls so some old FBI contacts and confirmed that Nancy and Parker had been out of the country.

Daniel confronted Chloe with the information. She tried to deny it. But, eventually she confessed to the whole scheme. She also realized that she needed to get some mental health, so she had her father pull some strings to get her into a facility. Chloe apologized to Daniel and Jennifer, said goodbye to Parker, and then left for a two-month stay in a treatment center. She would occasionally call home to talk to Daniel and Parker while she was away. Daniel and Jennifer again looked forward to starting a life together.

However, shortly after Chloe left, Jennifer's seventeen year-old son J.J. returned home from London boarding school. J.J., still struggling with his father's death, couldn't stand to see his mother with Daniel. So, J.J. began acting out towards Daniel -- vandalizing his MP3 player and car. J.J. also started using and selling drugs. Jennifer was clueless to it all.

When J.J. told Jennifer that Daniel was trying to come between them, Jennifer told Daniel that they needed to take a break. Daniel begged Jennifer to see that J.J. is just having a difficult time but they could help him through it together. Jennifer suggested that she and Daniel date secretly, but Daniel did not want to lie to everyone. So, Jennifer told him that she needed to put her son first and broke things off with Daniel.

But J.J. continued to be destructive. Upon finding out that his father had raped his aunt, J.J. was furious, both with the news and the idea that everyone had kept this information from him. He ran to the town square and threw a chair through the bookstore window, destroying a display of Jack's book. He got into a physical altercation with a man trying to stop him and was arrested for assault and vandalism.

The judge ordered J.J. to move back in with Jennifer and would suspend his sentence, giving J.J. a chance to show the court that he had changed. J.J. agreed in court, but immediately left as soon as he went home, telling Jennifer that she was a liar and he didn't want to be around her. He ended up at Theresa's house one night and the two of them smoked marijuana together. Theresa suggested taking a liquid ecstasy, known as G, before they slept together. J.J. didn't want to take the drug, so Theresa took both her and J.J.'s drinks and overdosed. She passed out.

Worried that she seriously hurt herself, J.J. picked up Theresa's phone and called Daniel to come help. Knowing that being caught with an overdosed female in his company would send J.J. right to prison, Daniel ordered J.J. to leave through the backstairs and not to tell anyone that he was there. Then, Daniel tended to Theresa, arriving at the hospital with her. When he arrived, everyone assumed that he had given Theresa the drugs because the two of them were sleeping together.

A stunned and scared J.J. went back home and told Jennifer and Abigail that he was done with drugs and was home for good. Jennifer was thrilled. J.J. also apologized to Daniel for putting Daniel in the position to have to let other people think that Daniel was sleeping with Theresa. Daniel told J.J. to keep you the guise that the two of them don't get along so that no one will suspect that J.J. was with Theresa doing drugs the night she overdosed.

Theresa seemingly took steps to make herself better, including talking to Maggie about attending NA and apologizing to Daniel. But the truth was that Theresa remembered everything that happened that night and was just pretending to have amnesia in order to drive a wedge between Jennifer and Daniel, thus making Jennifer's life worse.

When J.J. finally confessed to Theresa that he was the one who was with her the night that she overdosed, she laughed at him and told him that she was faking all along. J.J. was furious with her and wanted to tell everyone that it wasn't Daniel with her when she overdosed. But, Theresa showed J.J. a video she made that night of J.J. smoking weed. She threatened to send the video to the judge if J.J. didn't do exactly what she said. J.J. tried to tell Daniel, but Theresa stopped him and reminded him that she had blackmail info on him.

J.J. knew that he needed to do something to stop Theresa. So, he arranged for her to find a hospital check that was made out to Abigail. Theresa hired a guy to produce a fake hospital ID that identified Theresa as Abigail. Theresa took the check and her fake ID to an office supply store and bought debit gift cards, claiming they were for an employee incentive program. As the clerk grabbed the debit gift cards and rang them up for her, J.J. entered the store, surprising Theresa. He informed her that the clerk was actually a friend of his and her whole scheme was caught on the store's security cameras. He told her that they were even -- she couldn't release the video she had of him without him releasing the one he had of her. Theresa was furious, but turned her attention back toward Daniel.

She tried to play the victim card with Daniel, asking him to please tell her what happened the night he overdosed. But, Daniel kept pushing her away. She stole his keys from his locker one day and made a copy of his house key. She didn't know how, but she thought it would come in handy.

Worried that his mom and Daniel were still not back together because everyone thought that Daniel had slept with Theresa, J.J. decided to come clean. He told him mom everything, including that Daniel had been covering for him this whole time. Theresa went to Daniel and gave him one last chance to sleep with her before she released the tape of J.J. But, J.J. arrived at Daniel's apartment just in time and told Daniel about the video he had of Theresa. Daniel kicked Theresa out of his apartment and told her to stay away from him, J.J., and Jennifer.

Meanwhile, Nicole had enlisted Daniel's help in proving that Kristen drugged and raped Eric. Daniel ran a series of tests on Eric and found that there were traces of a masking agent in his blood. Working backwards, Daniel set about trying to find the limited few doctors in the country who worked with this specific drug. One of them was the doctor Kristen used, Dr. Chyka. When Stefano learned that Daniel and Nicole were snooping into Chyka, he sent Chyka to "take care" of the problem. Chyka was able to erase all of Daniel's files and flee Salem.

But, Daniel and Nicole weren't ready to give up. Using Nicole's connections at Titan TV, they were able to track the location of Chyka's safe house. They went there and held Chyka at gun point to get him to talk. When he refused, Daniel injected him with truth serum. He finally confessed to working for Kristen and supplying her with the drugs.

Just then another DiMera henchmen arrived at the safe house. Daniel managed to knock him out, but knew that he needed to get the man out of the house. So, Daniel drove the henchmen in the henchmen's car to a train station and left him there. Then, he took the train back to Salem where Nicole was to meet him with the proof. (She was supposed to keep drugging Chyka until he gave her the proof.) However, when he arrived, Nicole told him that Chyka had overpowered her and escaped before she could get the proof. Daniel reassured Nicole that they had done everything they could. He turned his attention back toward Jennifer.

When an embarrassing fake photo of Jennifer circulated around the hospital and unflattering comments about her flooded the hospital message board, Daniel and Jennifer assumed that it was Theresa. But, Theresa turned her attention towards Brady. She liked that her relationship with Brady bothered Maggie, Jennifer, and Daniel. Soon, she grew fond of Brady too, enough to turn down Liam Frazer's advances when he seemed to take an interest in her. But, one day at lunch with Liam, a picture of Jennifer fell out of his wallet. Theresa knew right away that Liam was obsessed with Jennifer and was behind the recent photos and messages.

Theresa ran to find Daniel to tell him about Liam. But, when Daniel found her, he didn't let her speak and immediately accused Theresa of sending the photos and messages. Theresa tried to tell him otherwise, but Daniel wouldn't listen. He threatened to have her fired from the hospital. Furious, Theresa went back to Liam and offered him the key to Daniel's apartment. Liam took it.

A few days later, Daniel arrived at the hospital to perform a surgery. But, a few minutes into surgery, Daniel had to leave. He collapsed and was hospitalized. Toxicology reports showed that he was high on opiates. Daniel was put on temporary suspension, per hospital policy, while the investigation took place. Daniel and Jennifer immediately suspected Theresa. Theresa knew that Liam was behind it, but she said nothing for fear of incriminating herself in the crime.

Theresa wasn't the only one who knew that Liam was behind the drugging. Nicole had run into Liam in the hallway of Daniel's apartment on the morning of the drugging. She didn't believe his lie about visiting another doctor in the building. But, when she confronted Liam about it, Liam revealed that he had blackmail information on Nicole, who was sitting on the proof that her boyfriend, Eric, could return to the priesthood if he wanted. Frustrated, Nicole did everything she could short of ratting on Liam to Daniel.

Nicole tracked down Liam's ex-wife in hopes to learn where he may store the proof he had against her. Liam's ex-wife tells Nicole that Liam is a dangerous man who becomes obsessed with women of a certain look - mainly petite, blond hair, and blue eyes, just like Jennifer. Nicole knew that Jennifer was in danger too. But, Nicole never found the proof.

A few days later, when Nicole learned that Jennifer was out on Smith Island alone, she rushed out to be with her. Nicole knew that Liam wouldn't miss the opportunity to attack Jennifer when she was alone. Nicole go to the island just in time. Liam had taken Jennifer hostage at gun point. Nicole managed to knock Liam out long enough for them to run out of the cabin. But, Liam regained consciousness and followed them.

But this time, Daniel had arrived at the island looking for the two women as well. He attacked Liam. During their struggled, Nicole was able to get the gun away. She shot, hitting both of them. Daniel suffered only a flesh wound. But Liam was more shaken up. He limped around the island until collapsing, impaling himself on a fallen tree branch and dying. Daniel, Nicole, and Jennifer called the police and left the island.

A few days later, Jennifer realized that she'd lost the necklace Daniel gave her during the struggle. The two of them went back to Smith Island to look for it. However, Daniel found some mysterious looking paperwork in the woods. He'd recognized it because he saw Nicole with the same shredded-and-put-back-together paperwork a few weeks earlier. He confronted Nicole with the paperwork. He knew it was the proof because he'd seen it in her hotel room earlier and she'd explained it away as a hoax from Stefano. This time, Nicole couldn't talk herself out of it. Daniel told Nicole to tell Eric, or he would.

Nicole didn't tell Eric the truth. Instead, she told Eric that they needed to elope because Daniel was in love with her. Eric was shocked, but agreed. They made plans to leave town. When Daniel heard this, he went to Nicole's hotel room to confront her again. However, Jennifer was standing outside the room and heard the whole story. She ran right to Eric and told him everything.

Daniel was furious with Jennifer for taking matters into her own hands and not trusting that Daniel would do the right thing. So, Daniel broke up with her. Jennifer tried for months to get him back. Despite still loving her, Daniel couldn't get past what Jennifer did and the fact that Jennifer still didn't believe that she did anything wrong.

To get some distance from Jennifer for a bit, Daniel decided to attend a medical conference in St. Louis. However, he was attacked the second he walked into his room. When he woke up tied to a chair, he saw Kristen. She wanted to talk to Brady again and was going to use Daniel as bait. But, Daniel was able to turn the tables on Kristen, capture her, and smuggle them both into the back of a truck that was headed for Salem. When they got there, Daniel marched Kristen right to the police station to face charges for her previous crimes.

But Kristen was able to blackmail her way out of the charges. And since she was in Salem, she decided to go after Brady again. Daniel was worried about his friend, not only because of Kristen, but because Brady had gotten involved with Theresa Donovan, another troublemaker. Brady was in a bad place because his father was in a coma after Brady supposedly attacked him. (Brady was too high to remember anything, so Theresa's account of the attack is all they had to go on.) Daniel tried to comfit Brady. Daniel also couldn't help but notice that Theresa was visibly nervous each time someone mentioned John possibly waking up. Kristen noticed it too and shared her suspicion with Daniel -- Theresa was actually the one who hit John, not Brady.

While Kristen investigated Theresa, Daniel turned his attention back toward fixing things with Jennifer. Despite his problems with Jennifer, Daniel still maintained a friendly relationship with J.J., who would come to Daniel for advice about his new girlfriend Paige. Specifically, J.J. was having problems with the fact that Paige's mom was Jennifer's high school rival. Daniel knew Paige because she did her observations at the hospital. He liked her and trusted both Paige and J.J. so he gave them keys to his apartment to use so that they didn't always have to be around Eve and Jennifer. Daniel also gave J.J. advice when it came to how to tell Paige about his father. But, Jennifer was furious when she found out that Daniel had given them keys to his apartment. She told him that they were done forever.

At the same time, Kristen was playing Brady a recording of Theresa confessing to hitting John. But Brady accused Kristen of making up the recording. He told her that there was no hope for them to get back together ever. So Kristen went to Daniel's apartment to give him the recording and say goodbye. But, she found a drunk and distraught Daniel instead. They argued. Eventually, their rage turned into passion and they headed for the bedroom.

Brady couldn't forget the recording, so he went to talk to John about it. Outside of John's room, Brady heard John and Theresa talking about the night of John's attack. He was furious and confronted them both. John told the truth but Theresa continued to deny it. She swore that Kristen doctored the recording. Brady rushed to talk to Daniel about the recording, but instead walked in on Daniel and Kristen in bed together.

Daniel and Kristen didn't even notice Brady standing in the doorway. He left. A few minutes later, they did stop before things progressed further. They got dressed and both agreed that what almost happened was a mistake.