This article is part of Yahoo's 'On This Day' series

Britney Spears burst onto the music scene at just 16 clad in a school girl’s uniform in the music video for her debut single, ...Baby one more time. Now, as the pop music icon celebrates her 40th birthday, we’re looking back at some of the standout moments from her headline making career, including her most memorable performances.

A star is born

Britney Jean Spears was born on 2 December 1981 in McComb, Mississippi, to parents Jamie and Lynne Spears. Spears was raised in Kentwood, Louisiana, where she showed an affinity for performing at a young age.

“I knew she was special, really like around four,” her mother Lynne told Oprah Winfrey in 2002. “But then by the time she was seven, I started really seeing star quality on the stage because she was a shy child, but when she’d get on the stage, she had a totally different personality.”

Star Search

In 1992, Spears performed for Ed McMahon on the hit-series Star Search. Spears won her initial performance singing the Ziegfeld Follies song, I Don’t Care. Spears advanced to a second round where she lost out after performing. Love Can Build A Bridge.

Britney's Mouseketeer Days

In 1993, Spears landed a role on The All New Mickey Mouse Club. The 12-year-old was cast alongside fellow future superstars like Justin Timberlake, Christina Aguilera and Ryan Gosling.

"It was a great time," Spears said of her Disney days. "It was probably one of the most special times in my life."

Princess of Pop

In 1999, Spears released her debut album which included hits such as Sometimes,” (You Drive Me) Crazy and, of course, ...Baby One More Time. She later told Rolling Stone that she purposely tried to alter her voice for debut single.

Watch: Britney Spears goes on romantic 40th birthday trip

“I wanted my voice to be kind of rusty,” she said. “I wanted my voice to just be able to groove with the track. So the night before, I stayed up really, really late, so when I went into the studio, I wasn’t rested.”

Britney's Rolling Stone Cover

In 1999, Spears landed a spot on the cover of Rolling Stone. While the then-17-year-old’s scandalous pose and ensemble raised eyebrows and even sparked backlash, it ultimately became an iconic milestone in her career.

Britney takes the Grammys

In 2000, Spears attended her very first Grammy Awards. While she, unfortunately, did not take home any awards that evening, she did turn heads on the red carpet in a white, Marilyn Monroe-esque gown.

Spears would go on to win her first and only Grammy in 2004 for Best Dance Recording for her song, Toxic.

A legendary performance

Spears put on a show at the 2001 VMAs that fans would never forget. While singing her sultry hit, I'm a Slave 4 U, off of her third album, she wowed fans by bringing a python on stage and using it as a prop during her dance number.

The snake’s handler, Michael Hano, later revealed to TODAY that Spears was initially afraid of the snake, but warmed up to it quite quickly.

“She was very good,” Hano said. “She was very focused and initially she was scared of the snake, but you could see that she was able to focus and kind of push [herself] to be able to work with the thing and look comfortable doing it.”

Britney takes Hollywood

As Spears’ music career began to make serious headway, she decided to try her hand at acting. In 2002, Spears took on a leading role of Lucy in Crossroads, also starring Taryn Manning, Zoe Saldana, and Kim Cattrall.

Manning later revealed on This Is Paris podcast that Spears was kept under tight supervision onset.

“She was never allowed to talk to anybody,” she said. “I don’t know if she was ever allowed to just have a friend, to be honest with you. I don’t know for sure, but it didn’t seem like she could just call a friend and go kick it. Way before [the conservatorship].”

The end of Britney and Justin

After three years of dating, Spears and boyfriend Justin Timberlake went from wearing matching denim outfits to a messy public breakup complete with cheating rumours.

Timberlake subsequently released Cry Me A River which was allegedly aimed at Spears.

Locking lips with Madonna

In 2003, Spears managed to shock fans by locking lips with Madonna while performing alongside the Live A Virgin singer and Christina Aguilera.

Britney and K-Fed tie the knot

While Kevin Federline started off as Spears’ backup dancer, it wasn’t long before things began to heat up. The pair made their relationship public in 2004 and tied the knot that same year.

“We just hit it off right away,” Federline told People in 2008. “I was madly in love with her. Everything just seemed so right. I didn’t see it as too fast or too slow.”

Britney's baby joy

After tying the knot and moving in together in Malibu, Spears dropped hints that she wanted to start a family. “I can see myself as a mom. Next year at 23, I am so there,” she revealed to People in 2004.

Britney's brood

Spears and Federline wasted no time expanding their family after welcoming their first son in 2005.

In September 2006, almost a year to the day after the birth of her first son, the couple welcomed their second son Jayden James.

Britney's divorce news

In November 2006, just months after welcoming their second child, Spears and Federline announced their divorce, citing irreconcilable differences.

“Opposites attract,” Federline told People just days before the divorce announcement. “If she gets mad and she yells at me, it just turns me on more, ya know?”

Gimme More performance, 2007

Fans were concerned that Spears’s highly publicized mental health struggles had taken a toll on the star following her performance of Gimme More at the 2007 MTV VMAs.

“She was just plain nervous because of all the hype and she’s embarrassed,” a source revealed to People following the backlash.

“She looked disappointed,” another source added. “She was extremely nervous. It’s been awhile since she’s done this, and she was performing in front of all her peers, on live TV. She just got out there and froze.”

Conservatorship begins

Spears’s infamous and controversial conservatorship took hold in 2008 after she was put ​​under a temporary psychiatric hold in Los Angeles.

Her father, Jamie Spears, and attorney were granted temporary (then permanent) control over her assets and business affairs.

Months before the conservatorship, Spears released Blackout — an album that Rolling Stone has dubbed her best album and a "misunderstood masterpiece" that included hits like Gimme More and Piece Of Me.

Britney makes a comeback

During the early years of her conservatorship, Spears released two albums under a new label, RCA Records – Circus in 2008 followed by Femme Fatale in 2011.

The two iconic albums included some of Spears’ most renowned hits, including Womanizer, If U Seek Amy, Circus, Hold It Against Me and Till The World Ends.

Britney takes Las Vegas

Not long after the release of her 8th studio album, Britney Jean, in 2013, Spears announced and began her Las Vegas residency, Piece of Me, at The Axis at Planet Hollywood.

The show went on to be a Sin City staple, and was extended until 2017 and went on to gross more than $137m.

#FreeBritney movement gains momentum

In 2019, Spears abruptly ended her Las Vegas residency. The star's longtime manager, Larry Rudolph, told reporters that Spears had made it clear she had no intention to perform and alluded to some mental health issues making it difficult for the star.

"I don't want her to work again 'till she's ready, physically, mentally and passionately," Rudolph told reporters. "If that time never comes again, it will never come again."

Rumblings of Spears's unhappiness began dominating headlines. While the #FreeBritney movement began in 2009, it wasn’t until the release of the documentary, Framing Britney was released in February 2021 that things started to progress legally in Spears's favour. The film shed light on the abuse of her conservatorship and sparked public outrage on her behalf.

Free at 40

After nearly 14 years, a Los Angeles judge accepted Spears’s appeal to terminate her conservatorship, giving her the freedom to make her own financial, professional, medical, and personal decisions for the first time since 2008.

“As of today, the conservatorship of the person and estate of Britney Jean Spears is hereby terminated,” Judge Brenda Penny said.

Spears later took to Twitter to celebrate, and praise her fans for their hand in the #FreeBritney movement.

"Good God, I love my fans so much it’s crazy! I think I’m gonna cry the rest of the day! Best day ever. Praise the Lord. Can I get an Amen? #FreedBritney,” she wrote.

Watch: Britney Spears hits back at paparazzi for photographing her at public bathroom