"I've been in love with him since not long after we met," Lambert said of Shelton in early 2010
Credit: Jason Merritt/Getty

After 10 years together, country superstars Blake Shelton and Miranda Lambert are calling it quits. Subscribe now for an inside look into their shocking split, only in PEOPLE.

Their marriage may be over, but Blake Shelton‘s memory of first meeting Miranda Lambert is still etched vividly in his mind.

It was 2005 and the country stars were partnered together on a duet of David Frizzell and Shelly West’s “You’re the Reason God Made Oklahoma” at the CMT 100 Greatest Duets concert.

“Every time I hear [that song], it’s like I instantly go back there,” Shelton told PEOPLE in December of the duet.

Lambert has said there was “inevitable chemistry” between them on stage. But at the time, Shelton was married to his first wife Kaynette Williams.

“I knew better, like, this is off limits,” Lambert told Dateline in 2011. “My parents are private investigators for God’s sake. I’ve seen this my whole life – affairs. Of all people to know better, I know better than this.”

Less than a year after the duet, Shelton divorced Williams (“I just really don’t think I was ready to be a husband,” he told PEOPLE in 2007) but that didn’t make a relationship between the busy superstars any easier.

“In the early days when it was easy to give up and say, ‘This is too hard.’ She’s the one that always found a way,” Shelton said of Lambert in November 2012.

And despite the difficulties, it was clear to Lambert’s mother Beverly that Shelton “brought the very best” out of her daughter.

“He brings out things that I had not seen before, like a really intriguing sense of humor,” Beverly added in November 2009.

Forgoing dinner-and-a-movie dates, Lambert and Shelton enjoyed a courtship full of hunting trips, boat excursions, evenings of friends and their shared “habit,” drinking.

“I’ve been in love with him since not long after we met,” Lambert said of Shelton in early 2010. “We are best friends.”

The best friends were out in the woods of Shelton’s native Oklahoma when Shelton proposed with a diamond and platinum ring on May 9, 2010.

“I was wearing a camo jacket and no makeup. It was very country, perfectly redneck and totally us,” Lambert said later that month. “I don’t think I said yes – I was just freaking out.”

“We’re meant to be together,” added Shelton that November.

By the next May, the two were officially wed.

“You could really see how in love they were,” their pal Neil McCoy said in July 2011 of their May 13 ceremony in Lambert’s native Texas.

Shelton and Lambert “were just giddy,” added Beverly. “She was like, ‘We did it! We did it! Tell me, was it perfect?’ And he said, ‘Honey, it was perfect!’ ”

Though their schedules would become more and more chaotic through the years (Shelton became a coach on The Voice in 2011 as Lambert’s solo career soared), the couple mandated they be able to see each other at least once every two weeks and savored their time spent together at their sprawling Tishomingo, Oklahoma, home.

“We live in the middle of nowhere and have a totally different life away from work,” Lambert said in April 2014. “We do the things we sing about in our songs – we go four-wheeling, we back-road, we fish, we eat at my mother-in-law’s at least twice a week.”

As they settled into married life, Shelton and Lambert agreed to discuss a time line for having kids once she turned 30. But that milestone came and went without any news of a pregnancy – a product of their busy schedules, according to Lambert.

“I don’t want to have children and raise them on a plane or a bus,” she said in November 2012.

Throughout their marriage, Lambert and Shelton faced rumors of pregnancy, cheating, and splits. But through it all, the couple always presented a united front that everything was just fine.

“It’s not easy when everyone is trying to tear you down, but you make a commitment and you stick to it. In other parts of the entertainment world, it sometimes seems like marriage is so disposable,” Lambert said in April 2014. “But country has some enduring marriages – Johnny and June, George and Nancy, Faith and Tim. I’m thankful we have those role models. I feel like our peers are rooting for us. They’re holding us up.”

But that support from their peers was not enough to make the four-year marriage last. On Monday, the couple released the following statement to the Associated Press:

“This is not the future we envisioned. And it is with heavy hearts that we move forward separately. We are real people, with real lives, with real families, friends and colleagues. Therefore, we kindly ask for privacy and compassion concerning this very personal matter.”

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