The Outlander timeline begins when a young woman, Claire Randall, accidentally steps into a stone circle in the Highlands and is transported 200 years back in time. As the series continues, viewers discover that Claire will meet a few others who have discovered the secrets of the stones, and she herself will return to her own time, and back again, eventually having her daughter follow.
There are a few "rules" to this type of time travel using magic stones. A traveler will end up approximately 200 years in the past, based on their own time. Time also runs at a consistent speed, and characters age at the same rate. There are multiple places around the world that allow people to travel, and anyone passing through one of these spots will end up at the same spot in the other timeline. Gemstones are also used to safely pass through the stones, and some believe sacrifice is also needed.
With all this wandering back and forth between centuries, Outlander has an unsurprisingly complicated timeline, not least because the series tells the two timelines simultaneously, weaving them together to explore Claire's story.
Outlander Season 1's Timeline
Outlander season 1 is a relatively simple one, in terms of time jumps, and only two time periods exist here. The series begins in the 1940s, as Claire and her husband Frank are reconnecting after WWII. They travel to Scotland together, which is where Claire accidentally stumbles through the stones, into the past. There, she becomes the guest/prisoner of the locals, including Jaime Fraser.
Spring 1945: Claire and Frank Randall are on their trip to Scotland to rekindle their romance after so long apart. On Beltane (May 1) Claire and Frank see some local women at a stone circle (Craigh Na Dun), performing a ritual that appears to be magical/druidic. Claire later returns to the circle to investigate a plant she saw, and is magically transported back in time.
May/June, 1743: Claire wakes up at the stones on May 2nd. A redcoat, the ancestor of her husband (Jack Randall) attempts to take her prisoner, but she is saved by locals. Claire is taken to Castle Leoch, the seat of Clan McKenzie. At Castle Leoch, she learns about the Jacobite rebellion brewing, and meets a local wisewoman (Geillis), and a young woman (Laoghaire) who has her eye on Jamie. Claire and Jamie marry, in order to keep Claire safe from the Redcoats.
Summer 1743: After their wedding, Claire tries to escape, to return to the stones and, hopefully, her own time. However, she is captured by Jack Randall, and she's nearly assaulted before Jamie rescues her (again).
October, 1743: In October, Geillis and Claire are accused of witchcraft. Both women are nearly burned at the stake, but Jamie saves Claire, leaving Geillis to her fate. Claire is honest with Jamie about where she comes from, and although he offers to take her safely to the stones, she decides to stay.
Winter, 1743: Claire and Jamie are at his family home of Lallybroch, when Jamie is betrayed to the Redcoats and taken prisoner at Wentworth Prison. There, he is tortured by Jack Randall, and sentenced to be executed, but Claire is able to rescue him.
Spring 1945 (reprise): Back in post-war Scotland, Frank Randall is searching for his missing wife, but when no trace of her is found, the police assume she simply ran away.
Outlander Season 2's Timeline
Outlander season 2 presents a change of scenery for Claire and Jamie, as they travel to France in the hopes that they will be able to thwart the Jacobite uprising and prevent the slaughter that Claire knows is coming. They must do this secretly, though, as publicly (at least, in their circles), Jamie must be seen as a supporter of Bonnie Prince Charlie. Despite their best efforts, Claire and Jamie fail to stop the coming war, and return to Scotland to do what they can to limit the damage.
January 1744: Claire works to heal the physical and emotional damage done to Jamie at his time in Wentworth Prison, and reveals to him that she is pregnant.
February 1744: Claire and Jamie head to France.
Spring/Summer 1744: Claire and Jamie work their way into Prince Charles' social circle. Jamie takes a young boy named Fergus into his employ, and they learn that Jack Randall is not dead. Randall comes to Paris and attacks Fergus, prompting Jamie to challenge him to a duel, get thrown in prison, and cause Claire to miscarry.
Fall 1744: Claire and Jamie return to Scotland.
August - December 1745: Jamie receives a letter, saying Charles Stuart has declared he is rightful King, and is coming to Scotland. At first, the Jacobites seem to succeed, taking over various cities. Claire travels with Jamie, treating the wounded.
April 1746: Culloden. Jamie will fight in the battle, but he wishes Claire to be safe, so he returns her to the stones. Pregnant once again, she passes through, sobbing. Jamie returns to the battle, even though he knows he will lose.
April 1948: Claire returns to the 1940s, two months pregnant and heartbroken. She reunites with Frank, expecting him to leave her, but he stays. He has been offered a teaching position at Harvard, and the two move to Boston to raise her child as Frank's.
Outlander Season 3's Timeline
Outlander season 3 is where the timeline starts to jump back and forth between Claire in Boston and Jamie in the aftermath of Culloden, with the first half of the season taking place in both times as the lovers are kept apart for many years. Then, the second half of the season sees Claire and Jamie reunited and also sees the location shift a third time, from Scotland all the way to Jamaica, as Claire and Jamie rush to rescue Young Ian, Jamie's nephew who has been taken by pirates. It's an action-packed season, and one that covers a huge span of time incredibly quickly, not all of which happens on-screen.
1752: Jamie has been living secretly near Lallybroch since surviving Culloden, and is struggling to stay hidden and keep the English from harming his loved ones. After soldiers question his sister Jenny and then capture and cut the hand off Fergus, Jamie decides to have Jenny turn him in. He goes to Ardsmuir Prison.
1755: A new warden of Ardsmuir, Lord John Grey, takes over and develops a relationship with Jamie.
1756: Ardsmuir is closed, and Grey allows Jamie to work out his sentence as an indentured servant at the estate of Lord Ellesmere. He is blackmailed into sleeping with Geneva, the Lord's young fiance, and gets her pregnant. She died in childbirth, and Ellesmere tries to kill the child. Jamie kills Ellesmere, Grey helps them cover it all up, and Jamie stays on, with his child being raised as the young Lord, until 1764, when he is paroled and returns to Lallybroch.
1765: Jamie marries Laoghaire, but the two are miserable. He then leaves her for Edinburgh, where he opens a print shop.
1949: Claire and Frank are trying to rebuild their marriage and raise Claire's daughter, Brianna, as their own.
1950s: Claire goes to medical school, becoming the only female student. She manages to succeed, graduating as a doctor while raising her child with Frank. Frank, however, is having an affair, which Claire finds out about. They stay together for Brianna.
1966: Brianna graduates high school, and Frank is offered a position at Cambridge. He and Claire argue over what will happen next. Frank is killed in a car crash.
1968: Brianna, who now knows the truth about Claire and Jamie, travels with her mother back to Scotland to try and discover what happened to her father. There, they learn that Geillis Duncan traveled back in time intentionally, in May of this year, and Jamie has survived Culloden. While Claire decides to return, Brianna starts a romance with Roger Wakefield.
Claire & Jamie Reunited:
1766: Claire and Jamie are reunited in Edinburgh after 20 years. The two return to Lallybroch, but Jenny isn't thrilled to see Claire again, believing that she abandoned Jamie after the battle. Laoghaire is even less happy about her return. This is resolved, somewhat, but Laoghaire demands money from Jamie, and he found out about hidden Jacobite treasure when in prison. They go to collect it, but as Young Ian is trying to get it for them, he is taken by pirates.
1767: Claire and Jamie travel to Jamaica to save Ian. There, they meet Lord John Grey, who is now governor, and Claire learns about everything that happened while she was back in her own time. They also run into another familiar face - Geillis. She has taken Ian captive. She is searching for gemstones and intends to travel through time again, using a cave on the island and Ian as a sacrifice. Grey is able to make sure that Jamie is safe, and Claire saves Ian. They intend to head home to Scotland, but are shipwrecked, and wake up on a beach in the New World.
Outlander Season 4's Timeline
The most recent season continues on a split timeline, because while Claire and Jamie are reunited in the 1700s, Brianna and Roger are still back in the 20th century for the first half of the season, before Brianna eventually decides to follow in her mother's footsteps and do a little time traveling of her own. Although, like the previous season, the two couples do eventually meet up in the past, bringing the timelines together again.
Claire & Jamie's Timeline:
April 1767: Shipwrecked off the coast of Georgia, Claire and Jamie manage to find their way to North Carolina, meeting a nefarious pirate-type named Stephen Bonnet along the way. There, Jamie is offered land and incentives to stay and help colonize, so they stay. Over the next few months, they head up to Aunt Jocasta's plantation, as she is a relative of Jamie's, and they can figure out where to settle from there.
August 1767: Claire, Jamie, and their family decide on a piece of land, naming it Fraser's Ridge. They start to settle in and build a home, recruiting others to settle nearby.
Brianna & Roger's Timeline:
1971: Brianna and Roger are growing closer. They have some ups and downs, but it seems as though they may reconcile when Roger discovers some historical records showing where Claire and Jamie were living in North Carolina. He also discovers that Claire and Jamie were killed in a house fire. Brianna decides to head back through the stones herself. Roger follows her, leaving both in 1769 Scotland.
The Fraser Family Timeline:
September 1769: Brianna and Roger take separate ships to the New World, then meet in Wilmington. The two are hand-fasted, but she later storms off, and then has the misfortune of meeting Stephen Bonnet, who rapes her. Thankfully, she then finds her parents, and they head back to Fraser's Ridge. Roger attempts to follow them, but thanks to a series of misunderstandings, Jamie believes that he is the one who attacked Brianna, beats him to a pulp, and hands him over to the local Mohawk tribe. Brianna reveals that she is pregnant, and heads to Riverrun to safely have the baby.
February 1770: Confusion over Brianna's attacker is cleared up, and Jaime and Ian head to the tribe to try and get Roger back. Ian offers to be traded for Roger, and is adopted into the tribe.
May 1770: Brianna has her baby in Rivverrun.
Weeks later: Claire and Jamie head to Riverrun, and tell Brianna about Roger. Roger rides in to join them, saying that he will raise the baby as his own. Jaime is then approached by a band of Redcoats, who have ridden up to find him and request that he forms a militia.
What's Next For Outlander?
Unlike previous seasons, the upcoming season of Outlander will be the simplest one yet in terms of timeline, because all the major players are now together in the colonies. There will certainly be plenty of adventure and more information coming to light about time travel, but it should be otherwise fairly straightforward, which will be a breath of fresh air for the show.