Canon Timeline.
1952
November 5th - Lionel's born; Faye is 26
1953
September - Greg is born, Lionel is not yet one
1955
June - Val is born, Lionel is two
1959
January - Anne is born, Lionel is six
Late 1959 - Early 1960
Ward loses most of his fortune. Faye finds out and takes control, selling their house and everything they can do without. The family moves into a smaller, cheaper house outside of Beverly Hills. Ward can't take the misfortune and cheats on Faye. They split, with Faye getting a job as an AD. The one family nurse kept on takes care of the kids as Faye works 16 hour days. Months later, Ward finds his way back, humbled with a job in a bank and wanting to see his kids again. Lionel is the only one not outright happy to see Ward, and has to be encouraged by Faye to say hi to his father. Faye and Ward eventually get back together. Lionel turns seven during the split.
1963
Lionel falls in love with photgraphy, and gets his first camera. He is 10.
1964
Faye is a critically acclaimed director by now, and gets Ward to start up his own production company. The two gain success, and are able to move back into Beverly Hills. Lionel is 11, and celebrates his 12th birthday in the new house.
1967
At 14, Lionel begins to win awards for his photography.
1971
June - Lionel is 18, and graduating from Beverly Hills High School. Ward and Faye give him a red Ford Mustang convertible (with white side panels and red upholstery) as a graduation gift. Lionel spends most of his after-grad party talking to John Wells, Greg's best friend.
July - Lionel moves into an apartment right off the UCLA campus in Westwood with four other guys moving in once the fall semester starts. He gets his first job at Van Cleef & Arpels on Rodeo Drive.
August - Lionel starts his first semester studying Photojournalism at UCLA (book: cinematography, movie: photojournalism)
November - Lionel turns 19. While visiting Faye on set, Lionel meets Paul Steele, the star of her new film. Paul is 28, and after a week or so of talking during Lionel's visits, Paul asks Lionel out to eat. They end the night going up to Paul's mansion in the hills, and Paul says he knows Lionel is gay, and he is well. Lionel admits it as well, and they start an affair, keeping it secret from everyone, Faye included.
1972
April - Paul grows tired of the relationship, and while it doesn't end badly, it does end. They don't see each other again (not for the time up to when Lionel arrives on the island, at least).
June - Greg graduates from BHHS. Lionel spends most of Greg's party talking to John just like his own the year before, and John confesses that he's glad to be finally leaving high school and going to UCLA. Lionel invites John to move into the apartment with him, since they need one roommate again. John agrees. He's finished moving in a few days later, during which John and Lionel have been spending a lot of time together. Worried about his own feelings toward John, Lionel is about to confess that he's gay when John comes out first. Lionel admits he is as well, and the two spend a relieved afternoon talking about their past experiences and getting to know each other even more. It's easy from there for them to fall into a relationship, even though they know they have to keep it a secret from everyone they know, especially their roommates.
A week later, Lionel comes out to Faye.
November - Lionel turns 20.
December 25th - After Christmas dinner with his family, Lionel returns to his apartment. Everyone else has gone home for the holidays, and John's back from dinner with his own family. Ward stops by the apartment to talk to Lionel, and catches John and Lionel together. Words (and a punch) are thrown around, and Ward tells Lionel he's no longer his son and is never allowed back home or into the family. When he returns home, Ward tells his family that Lionel is no longer allowed home. Anne decides to run away, and stops by Lionel's apartment, but the boys are too worn out to deal with anything more for the night, so they ignore the knocking. Anne leaves a note letting Lionel know she'll always love him, and disappears.
1973
June - After Anne runs away, Lionel is convinced she's in San Franciso in the Haight Ashbury district, a haven for runaways. Lionel and John take time off form college to go up there, and by June they've spent six months living out of a hotel, spending every day searching the streets for Anne. One day, John finally thinks he spots her, and a few days later with the help of the police, they finally get Anne. She'd joined a cult of sorts almost as soon as she'd arrived in the city, been brainwashed and got addicted to LSD. She was also pregnant with someone's child, and was still only 14. Lionel calls Faye, and she and Ward make their way up to bring Anne home. An uneven truce is struck between Ward and the boys while they're in San Franciso, though it's disappeared as soon as Anne is back home.
July - Although they're back home, John and Lionel no longer want to live in the apartment, tired of lying to everyone and ready to admit what they are. Anne can't stand to be home since she hates everyone in her family but Lionel. Lionel and John rent an apartment with an extra bedroom and let Anne stay there with them until the baby is born.
October 12th - Anne goes into labor, and while she's been vehemently against giving up her baby, Faye and Ward still find parents to adopt it. Her relationship with Lionel gets a little strained as well, since he's not exactly stopping their parents from doing so. Anne never even gets to see the baby after it's born, something which she never forgives her family for - even Lionel. She's 14 when she returns to the Thayer home.
November - Lionel turns 21.
[The following events up to Lionel's arrival on TR are loosely based on movie canon. Some historical facts are smudged because the canon drove me insane. Let's also pretend The Godfather II came out a different year.]
1974
April - Greg, having been booted off his college football team for failing grades and finally leaving school, receives a draft notice. The family says goodbye to him a few days later.
July - Greg's company is flown into Cambodia a mere week after they complete basic. On his first mission out he steps on a land mine and there's nothing left of his body to send back. A funeral is held for him a week later after the family receives the news. While Ward tentatively takes the first steps toward making things right with Lionel, he still doesn't allow John to attend the funeral. Lionel accepts the peace offering, though he makes it a point to tell Ward that he has to accept John as well.
November - Lionel turns 22.
1975
April - Faye wins her second Academy Award, this time for Directing. The family minus Val attend.
September - Lionel and John exchange wedding rings. While not an official ceremony of any sort (they did it in their living room), it means just as much to both of them. They're both 22.
November - Lionel turns 23.
1976-1977
April 18th - Making the final gesture needed in mending the bridge between them, Ward officially invites John to join the Thayers for Easter Sunday dinner. John and Lionel accept, surprising Faye and the rest of the family. For the first time in years, Ward is glad to have his son back and Lionel is glad to be back home. The two leave the Thayer house, Lionel on cloud nine as it finally feels like things are falling into place the way they always should have. On the drive back home to their apartment, they get into a car crash. Lionel barely survives, and doesn't know John is dead until days later when he's in the hospital and out of surgery.
April - August - Lionel is in the hospital recovering for weeks, and still has to spend even more time after that in physical therapy.
September - February - While having had months of recovery and getting back on his feet, Lionel still hadn't had time to properly grieve over John. He starts therapy but finds it's easier to work through his grief with his photography, and that's all he'll do for months. Lionel turns 24 in November. In February he burns out a bit, but finally comes to a point where the loss of Greg and John is something he can cope with from day to day.
May - Lionel's art is opened in an exhibition, which is generally well received. The next morning he finds himself on Tabula Rasa.