Christina Aguilera was a 90s pop icon. In interviews, she only ever gets asked about one thing.

Christina Aguilera has an incredible voice. She's always had it. A clip from a 1994 episode of The Mickey Mouse Club shows her at age 13, belting out the Aretha Franklin classic 'Think'. 

Dancing enthusiastically behind her is a 12-year-old Britney Spears.

There were other stars of the future in The Mickey Mouse Club at the time, including Justin Timberlake and Ryan Gosling, but over the decades, it's Spears who's always kept popping up in the same frame as Aguilera, no matter what she achieves in her career.

Aguilera, daughter of musician Shelly and Ecuadorean-born soldier Fausto, started performing at the age of seven. She'd grown up in an unhappy home, with her mother walking out on her father after what Aguilera describes as "a lot of unpleasant things – a lot of pushing and shoving and fighting and quarrelling."

"Growing up, I did not feel safe," she told E! in 2009. "Feeling powerless is the worst feeling in the world. I turned to singing as an outlet. The pain at home is where my love for music came from."

Watch: Christina Aguilera performing 'Think' live at The Mickey Mouse Club in 1994. Post continues below.

Aguilera had been gifted with a four-octave range, but was also prepared to put in whatever work it took to make it to the top as a singer.

"As a child [entertainer], you're all pitted against one another, and other children are all about that grind, too," Aguilera told Health last year. "It's a weird space to grow up in."

When The Mickey Mouse Club was axed, Aguilera began focusing on her solo career, determined to put out an album while still at high school. She recorded 'Reflection', the theme song for the movie Mulan, when she was 17.

But Spears topped the charts before Aguilera. She was just 16 when she released '…Baby One More Time', along with the video of her in a school uniform. It went to number one in more than 20 countries and became one of the biggest-selling singles of all time.

Just months later, Aguilera released 'Genie In A Bottle'. The song was a hit before she even released a video, and also went to number one in more than 20 countries, but she couldn't avoid the comparisons to Spears.

The New York Post wrote about the "battle of the bubblegum divas", describing Aguilera as a "bleach blond lookalike" who was "duking it out" with Spears for the title of Teen Queen.

"It's frustrating always being compared to Britney because we are two very different artists," Aguilera was quoted as saying. "We both dance and sing but people have not yet had enough time to realise that there is a huge difference between us."

The hits kept coming for Aguilera, including 'What A Girl Wants' and her massive 2001 collaboration with Pink, Mya and Lil' Kim, 'Lady Marmalade'. By 2002 she was ready to head in a new direction with her album Stripped, where she co-wrote most of the songs, including the single 'Dirrty'.

Christina Aguilera while filming the 'Dirrty' music video. Image: Getty.

"The label wanted to push the cookie-cutter, kind of play-it-safe, almost virginal kind of imagery that wasn't me," she told The Sydney Morning Herald in 2002. 

"I really wanted to squirm away from that, because I really thought it was really fake and superficial and untrue of what I was about, and it was really really hard for me to live up to that anymore."

Aguilera released some iconic songs, including 'Beautiful' and 'Fighter', but for the media, her new direction was a chance to compare her to Spears one more time.

"I remember being hurt by these commercials on MTV, pitting Britney as the good girl and me as the bad girl," Aguilera told Cosmopolitan in 2018. "It's like, if I'm going to be demure and innocent, that's okay. But if I'm going to just be myself, I'm trouble."

Admittedly, it's partly Aguilera's fault that the media became obsessed with her rivalry with Spears.

In 2003, after the MTV Video Music Awards, all anyone could talk about was the opening number where Madonna kissed Spears. Madonna also kissed Aguilera, but that was barely seen, because straight after the Spears smooch, viewers got a shot of Justin Timberlake, who Spears had dated.

"They cut away to get Justin's reaction," Aguilera told Radio Andy in 2018. "I definitely saw the newspaper the next day and it was like, 'Oh well, I guess I got left out of that one'."

Soon after, Aguilera started sniping at Spears in the media. Aguilera told Blender that Spears seemed "very distant" during rehearsals for the VMAs.

"Every time I tried to start a conversation with her – well, let's just say she seemed nervous the whole time. She seems to me like a lost little girl, someone who desperately needs guidance."

Spears hit back in the following issue of Blender, telling a story about how Aguilera came up to her in a club after not seeing her for two years and tried "to put her tongue down my throat".

Image: Getty.

"I say, 'It's good to see you,' and she goes, 'Well, you're not being real with me.' I was like, 'Well, Christina, what's your definition of real? Going up to girls and kissing them after you haven't seen them for two years?'"

Aguilera wasn't done. 

When Spears was set to marry Kevin Federline in 2004, she took a dig at Spears' personal life.

"She's not trailer trash, but she sure acts that way," she told Us Weekly. "I can't believe that girl bought her own engagement ring! I've seen it, up close. It looks like she got it on QVC."

By that time, Aguilera was dating music producer Jordan Bratman. The two married in a lavish ceremony in 2005 – Aguilera sang at her own reception – and she co-wrote the hit single 'Ain't No Other Man' about her love for her new husband. They had a son, Max, before splitting in 2010. 

Aguilera started dating Matthew Rutler, a production assistant she’d met on the set of the movie Burlesque (a movie that reviewers liked to point out was not quite as awful as Spears' Crossroads) and they had a daughter, Summer, in 2014. 

The hits stopped coming but Aguilera stayed in the public eye as a coach on the US version of The Voice.

Aguilera had long matured beyond taking potshots at Spears, but the media wasn't prepared to let her forget her former Mickey Mouse Club co-star. 

Journalists kept asking her for her thoughts on the singer, especially when Spears finally ended her 13-year conservatorship in 2021.

Christina Aguilera today. Image: Getty.

On the red carpet at the Latin Grammy Awards, Aguilera had a new album to talk about, but was questioned over whether she'd had any communication with Spears.

Her publicist jumped in with, "No, we're not doing that tonight. I'm sorry."

As the publicist led her away, Aguilera said, "Yeah… but I'm happy for her."

Spears posted the video of Aguilera on the red carpet, sounding furious: "I love and adore everyone who supported me… but refusing to speak when you know the truth is equivalent to a lie!!!!"

The media went wild. The feud from two decades earlier was back on.

It looks like no matter whatever Aguilera ends up being known as – singer, songwriter, TV personality, actress – 'Britney Spears rival' will always be in there.

Feature Image: Getty/Mamamia.