Joaquin Phoenix and Rooney Mara's Relationship Timeline

The pair stunned on the 2020 Oscars red carpet. Phoenix would go on to win Best Actor for his performance in Joker. In his speech, he spoke passionately about bettering the world: "I think that's when we're at our best, when we support each other ... when we help each other grow, when we educate each other, when we guide each other towards redemption. That is the best of humanity."

After Phoenix's big win, the couple visited Monty's Good Burger in L.A.'s Koreatown to celebrate with plant-based burgers.

Phoenix and Mara met in 2012 on the set of Her, in which Mara played Phoenix's ex-wife.

Things weren't romantic right away for the costars. In fact, Phoenix told Vanity Fair in 2019 that he thought Mara didn't like him at all, but it turns out she was just shy.

"She's the only girl I ever looked up on the internet," he said. "We were just friends, e-mail friends. I'd never done that. Never looked up a girl online."

Phoenix and Mara reunited on-screen when they costarred in the 2016 Mary Magdalene. Mara played the titular role, and Phoenix portrayed Jesus.

"I was looking for something meaningful," Phoenix explained to T Magazine in 2017 on what drew him to the film. "I was looking for an experience. I was friends with Rooney."

The film wasn't released in the United States until April 2019, over a year after premiering in London in February 2018.

Phoenix and Mara made their first public appearance as a couple at the closing ceremonies for the Cannes Film Festival on May 28, 2017. The pair sat together and interacted like a couple, including holding hands and embracing after Phoenix won the festival's best actor award for his role in 2017's You Were Never Really Here.

"They were talking to one another nonstop," a source told PEOPLE at the time. "Small talk between them. Then they went for their car, and he's holding her hand like it was unconscious. Like it fits. They seem a totally natural and easy couple."

In September 2017, the actor told T Magazine that he and Mara live together in the Hollywood Hills. Although Phoenix did not share details on when the two started cohabitating, he revealed how they spend their downtime at home.

According to Phoenix (a self-proclaimed homebody), he's usually asleep by 9 p.m. and up by 6 a.m. Among the activities in his daily routine are answering emails, meditating, "chilling" with his dog, taking karate classes and eating.

Phoenix also said that he and Mara binge-watched the Netflix true-crime documentary The Staircase because Mara wanted to, and he let the cat out of the bag that his favorite movie at the time was Disney's 2016 animated film Moana. "I thought it was beautiful," he said, before changing his answer to The Lost City of Z.

The couple privately got engaged in 2019. Rumors of an engagement sparked when Mara was photographed wearing a large diamond ring on her left hand.

However, representatives for Mara and Phoenix did not comment when asked about their relationship status.

Phoenix and Mara are both passionate activists, and in 2019, they joined a protest together on National Animal Rights Day.

The couple marched in West Hollywood holding dead animals during the demonstration. At the end of 2019, Phoenix was named PETA's person of the year for his animal rights activism.

At the 2019 Venice Film Festival, Phoenix and Mara made a grand entrance for the world premiere of his film Joker. The couple was all smiles as they arrived on a boat. Phoenix wore a tux and Mara a white gown.

The movie would later win the festival's big prize, the Golden Lion, for best film.

After winning the inaugural TIFF Tribute Actor Award at the Toronto International Film Festival in September 2019, Phoenix used his acceptance speech to honor his late brother River Phoenix and thank his fiancée for her support.

"One last thing — somewhere here, I don't know where, is a filthy dragon, and I want to rip its wings off and fasten a blanket and sleep with it forever," he said. "I love you. Thank you."

Phoenix looked on lovingly as Mara posed for photos at the 2020 Golden Globes, where the couple made a rare appearance on the red carpet together.

Later that evening, Phoenix received the Golden Globe for best performance in a motion picture drama for his role in Joker.

The couple welcomed their first child, a son named River, after Phoenix's late brother, who died in 1993.

Russian filmmaker Victor Kossakovsky, with whom Phoenix worked on the dialogue-free documentary Gunda, confirmed the name of the couple's baby during an appearance at the 2020 Zurich Film Festival.

"He just got a baby, by the way," Kossakovsky said while speaking at the festival. "A beautiful son called River."

Mara later confirmed River's name when she mentioned her son in a Mother's Day 2021 campaign for Farm Sanctuary.