From the Oscars mix-up and Wonder Woman craze to the announcement of Beyoncé's babies and the #MeToo movement, a lot has happened in the last 12 months. 

Here are the top pop culture moments that helped define 2017. 

"Envelopegate" and the Oscars

What happened: Presenters Warren Beatty and Faye Dunaway walked onstage with the wrong envelope and announced that La La Land was best picture, instead of actual winner Moonlight. The La La Land team had already begun thanking people before producer Jordan Horowitz took to the mike to announce the mix-up. “Sorry, guys, hold on. There's a mistake. Moonlight, you guys won best picture. This is not a joke.”

Why it was a big deal: The best-picture award is the highest film honor in Hollywood, and an Oscar for Moonlight would’ve been a newsworthy underdog win even if the best-picture announcement was flub-free. The indie film, about a gay man confronting his identity, is the first winner to tell a story primarily about and starring black people that isn’t about racism, the civil rights movement or slavery. 

More: Here's how the worst flub in Oscar history went down

More: Don’t let the Oscars' mix-up ruin legacy of ‘Moonlight’

Ariana Grande, at the One Love Manchester benefit concert in June, is scheduled to perform at 'A Concert for Charlottesville.'

Ariana Grande's benefit concert

What happened: Grande was performing at the Manchester Arena in northwestern England in May when a suicide bomber detonated an explosive device, killing at least 22 people and injuring more than 100

Why it was a big deal: The tragedy renewed the public's concerns with concert safety, and prompted the Department of Homeland Security to say there is no evidence of credible threats against music venues in the U.S. 

Grande's sold-out benefit, which was planned after the first terror attack, was held in June. The event became a unifier for thousands of attendees and several guests, including Miley Cyrus and Justin Bieber. The joy and dancing from the event was so contagious, even a police officer was caught on camera enjoying the music. Grande went on to become one of the most-followed celebrities in 2017, with 22 million new Instagram followers, putting her total at more than 115 million.

More: Undaunted, Ariana Grande leads emotional One Love show for Manchester

A dancing policeman won Twitter at Ariana Grande's Manchester concert

Las Vegas concert shooting

What happened: A gunman opened fire on the Route 91 Harvest Festival in Las Vegas, killing 58 and injuring more than 500.

Why it was a big deal: The incident has been called the deadliest shooting in modern U.S. history. It caused performers to cancel tour dates. And it put a spotlight back on issues of live event safety and gun control. However, despite calls for legislative action, proposals including those to expand background checks on firearms haven’t gotten anywhere. 

The event specifically impacted the world of country music: Jason Aldean, who was performing at the time of the shooting, visited victims in the hospital; The Country Music Association asked journalists not to talk about the tragedy and gun control at the CMAs, but reversed its decision at the urging of Brad Paisley and others; and country stars, including Caleb Keeter, spoke out about gun control for the first time

More: CMA apologizes, lifts media restrictions at CMA Awards

More: Las Vegas mass shooting raises new doubts about safety of live entertainment

The Harvey Weinstein saga and #MeToo movement

What happened: Men and women spoke out about harassment, using the hashtag #MeToo, in the wake of the news that movie producer Harvey Weinstein was accused by dozens of women of predatory sexual behavior spanning decades, which The New York Times and The New Yorker first reported in October.

Harvey Weinstein scandal: A complete list of the 83 accusers

Why it was a big deal: The accusations led to Weinstein's downfall: He was fired from the production company he started and figuratively blacklisted. Then, more high-powered Hollywood men fell. The #MeToo movement incited a deluge of sexual harassment and assault allegations. As a result, famous faces in movies, TV and elsewhere, including Kevin Spacey, Matt Lauer and Louis CK, have been summarily fired.

Celebrity responses to hurricanes Harvey, Irma and Maria

What happened: Hurricanes Harvey, Irma and Maria tore through Texas, Florida, the Caribbean and parts of the Southeast in August and September. The storms caused massive flooding, power outages and devastation for millions. Celebrities including Jennifer Lopez, Kevin Hart, J.J. Watt, Ellen Degeneres and the Kardashians challenged others to donate to hurricane aid organizations assisting victims. Lin-Manuel Miranda rounded up fellow Latino artists for the charity song Almost Like Praying to aid Puerto Rico, while Beyoncé, Justin Bieber and Oprah were among the celebs featured at the Hand in Hand telethon for victims of hurricanes Harvey and Irma. 

Hurricane Harvey: Jimmy Fallon's 'Tonight Show' to donate $1 million to J.J. Watt effort

Why it was a big deal: Celebrities from various backgrounds came togethe, raising millions of dollars through social media, multiple telethons and charity songs to benefit victims of the storms.

Lin-Manuel Miranda explains his new song for Puerto Rico, those Trump tweets

Beyoncé's pregnancy announcement

What happened: Beyoncé took to Instagram in February to announce her pregnancy — with twins! The elaborate photo shoot was the most-liked picture on Instagram for the year, with more than 11.1 million likes, and was only rivaled by her first photo — garnering more than 10.2 million likes — presenting her newborn babies, Rumi and Sir, to the world in July.

Why it was a big deal: It’s Queen Bey.

Prince Harry and his fiance, Meghan Markle, announced their engagement on Nov. 27, 2017 at Kensington Palace.

Prince Harry and Meghan Markle's royal engagement

What happened: The world’s most eligible royal bachelor was taken off the market in November with the news that he’s engaged to actress Meghan Markle. The announcement came a couple months after the couple made their first appearance together at Harry’s Invictus Games in Toronto.

Why it’s a big deal: Markle is the most atypical royal bride ever: She's a divorced, biracial, Jewish American.

Jimmy Kimmel's health care segments

What happened: Kimmel became the face of health care in entertainment when he opened up about his infant son’s health problems and emotionally pleaded for affordable health care coverage for all. His son, Billy, has had two surgeries to help treat his pre-existing heart condition.

Why it was a big deal: Health care reform was one of the tenets of Donald Trump’s presidential campaign, and major changes to the Affordable Care Act have fallen short in Congress since Trump’s inauguration. Kimmel often used his opening monologues to try to hold the administration and lawmakers accountable. 

Emotional Jimmy Kimmel discusses baby son's heart surgery

'The Crown' star Claire Foy will trade furs and ballgownsfor motorcycle leather when she stars as Lisbeth Salander in 'The Girl in the Spider's Web.'

The influence of The Handmaid's Tale

What happened: The 1985 novel by Margaret Atwood got a critically acclaimed screen adaptation on Hulu in April. The series, a dystopian tale of a group of women forced to become breeders under a new regime, was seen as more relevant than ever to anti-Trump audiences.

Why it’s a big deal: The show struck a chord with viewers. Not only did Handmaid’s Tale win five Emmys, including best drama, but women wore the red robes and white bonnets to courtrooms, and eventually the U.S. Capitol, as a way to protest bills seen as restricting women’s rights.

Review: ‘Handmaid’s Tale’ is a wake-up call for women

Taylor Swift's comeback

What happened: Look what you made her do. Taylor Swift returned after a year out of the public eye with a new look and a new album, Reputation. She also announced a massive 2018 tour.

Why it was a big deal: Swift’s album sold more than 1.2 million copies in its first week, becoming 2017’s fastest and best-selling album.

How Taylor Swift's 'Reputation' beat streaming to become 2017's best-selling album

Kendall Jenner's Pepsi commercial

What happened: Kendall Jenner appeared in a tone-deaf ad for Pepsi, which showed the model joining a protest in the streets and handing a police officer a can of the soda to help calm the tension. The wildly negative response to the ad caused Pepsi to pull the commercial and issue an apology. 

Why it was a big deal: The commercial appeared to make light of serious issues and the Black Lives Matter movement. Having Jenner — who has been accused of cultural appropriation along with other members of her famous family — at the center of the ad did not help. And it was problematic for Jenner, who became the highest-paid model of the year and top model as far as mentions on Tumblr.

Twitter takes Pepsi to task over tone-deaf Kendall Jenner ad

Ashley Judd, spoke at the rally at the Women's March on Washington in January, has also been vocal in the #MeToo movement.
Paul Morigi, WireImage

The Women's March

What happened: Millions of women, and men, marched in Washington, Los Angeles, New York and other cities across the world in January as a direct response to Trump's inauguration. The attendees marched to advocate for legislation involving women’s rights, LGBTQ rights and immigration reform, among other issues. Hundreds of celebrities joined the cause, speaking on stage at the various marches and walking alongside attendees.

Why it was a big deal: The marches helped lay the foundation for the current #MeToo movement, creating an environment where women could speak openly about their experiences and sparking other marches against injustices.

The most memorable quotes from the Women's March on Washington

❤️ #Repost @arod ・・・ Happy Birthday to Us!!! #leos 🇩🇴🇵🇷 #305

A post shared by Jennifer Lopez (@jlo) on

JLo and A-Rod's love story

What happened: Jennifer Lopez and Alex Rodriguez made their official debut as a couple at the Met Gala in May, and it’s been nothing but cute Instagram photos and loving interviews about their relationship ever since. The picture that Lopez re-posted from Rodriguez was her most-liked picture on Instagram for the year, picking up more than 1.6 million likes. 

Why it was a big deal: There have been a lot of tragedies in 2017, so romance between two of the world’s biggest stars is a silver lining.

Inside Jennifer Lopez and Alex Rodriguez' lavish 'baecation'

The hype around 13 Reasons Why

What happened: In March, Netflix released the first season of 13 Reasons Why, the adaptation of a 2007 novel about a high school girl, Hannah, who commits suicide and leaves a series of tapes explaining the lead-up to her death. The show immediately became a talker on social media.

Why it’s a big deal: The show sparked fears around the way suicide was depicted, and of teenage viewers making light of Hannah's death. The meme “welcome to your tape” was born. Meanwhile, the show encouraged families to have serious discussions of teen suicide after many viewers complained about the way the topic was handled. The controversial series has been renewed for a second season.

Gal Godot as Wonder Woman holding a shield and sword.
Warner Bros

The power of Wonder Woman

What happened: Wonder Woman became the best-reviewed DC Universe film and a box-office hero when it hit theaters in May. The Gal Gadot-led film already has a sequel in the works.

Why it's a big deal: Wonder Woman had the biggest opening ever for a movie directed by a woman with a $100.5 million debut, and presented a turning point for female representation on the big screen. Seeing the feminist film became an event, with fans dressing in Wonder Woman garb and posting about the movie to social media. Wonder Woman was the most-talked-about movie on Tumblr, and Gal Gadot was the second-most-popular actress mentioned on the social media site.