By 1991, Alice in Chains had already made their grand entrance with Facelift. Anthems such as "Man in the Box" and "We Die Young" proved this band were going to be one of the biggest of the decade. But no one had any idea what was coming next.

The quartet released their sophomore album Dirt on Sept. 29, 1992. It was their sludgiest, darkest work yet, and also their last with original bassist Mike Starr. Layne Staley and Jerry Cantrell's haunting vocal harmonies were back, and the music was heavier overall. Coming in right after the explosion of grunge, Dirt spawned five singles and spent 106 total weeks on the charts.

In celebration of the anniversary of one of the best grunge albums in rock history, here are 10 facts only Alice in Chains superfans would know about Dirt.

1. It's statistically their best album.

Many rock fans choose Dirt as their top AIC album, but the facts support the notion as well. Though their self-titled third effort debuted at No. 1 on the Billboard 200 and Dirt peaked at No. 6, the latter sold almost twice as many copies, making it their highest-selling album.

2. The effect of the Los Angeles riots.

In 1992, four police officers were acquitted for using violent excessive force on Rodney King. The indictment decision sparked what became known as the Los Angeles riots — and Alice in Chains had just entered the studio around the time that the riots began. The band admit that the fear and the chaos added to the level of darkness on the record.

"L.A. tore itself apart protesting police brutality," Cantrell told Vice. "We had to try to get out of the town without getting hurt. I think we took Tom Araya with us and went out to Joshua Tree for four or five days, and just kinda tripped out in the desert until things calmed down. And then we moved back into the studio and started recording—that’s how Dirt started."

3. The Rooster.

"Rooster," perhaps the band's most iconic song ever released, was inspired by Cantrell's relationship with his father, who had served in the Vietnam War. It's written from the perspective of his dad while he was trekking through the jungles and surviving.

“I certainly had resentments, as any young person does in a situation where a parent isn’t around or a family is split," the guitarist told Classic Rock magazine. "But on Rooster, I was trying to think about his side of it – what he might have gone through."

4. Layne Staley played guitar.

Though Cantrell has always been the group's primary songwriter, Staley did write quite a few songs in their catalog. His contributions to Dirt were "Hate to Feel" and "Angry Chair," which he wrote all on his own and even played guitar on.

5. Black gives way 17 years later.

Alice in Chains' first album with vocalist William DuVallBlack Gives Way to Blue, was released Sept. 29, 2009 — exactly 17 years after the release of Dirt. Many of the lyrics on the album were based on the loss of Staley, specifically the title-track.

6. SLAAAAAYYYYEEEERRRRR!

Slayer frontman Tom Araya provided guest vocals on the track "Iron Gland." Cantrell concocted the song out of a riff he played that bothered the rest of the band. He included it on the album as a promise that he'd never play it again.

7. The girl on the cover was not Layne Staley's girlfriend.

Staley was pretty inseparable from his girlfriend in the early '90s, Demri Parrott. Many speculate that she's the model on the cover of Dirt, but it was actually Mariah O'Brien, who was also on the cover of Spinal Tap's single "Bitch School."

"Everyone always asks if that is Demri on the Dirt cover," photographer Rocky Schenck told Revolver. "I think Demri's name might have been mentioned as a possible model once or twice, but it was never a serious consideration."

8. Would Wood?

"Would?" is a tribute to Mother Love Bone frontman Andy Wood, who died at the age of 24 in 1990 from an overdose. The influential singer's death also was the impetus for the formation of another Seattle outfit, Temple of the Dog.

9. The No More Tours tour.

Alice in Chains were invited to open for the Prince of Darkness on his No More Tours tour in 1992. Just before heading out, Staley broke his foot in an ATV accident. He still managed to hobble onstage with crutches and carried on as usual.

This tour also was the reason Mike Inez joined the band on bass after Starr's departure. He was Osbourne's bassist at the time when the band asked him to tour with them in Europe. "I say 'Ozzy, I've gotta talk with you,'" Inez told the Rich Eisen Show. "I said, 'Alice in Chains guys want me to go to Europe.' And then he looks me right in the eye and says, 'If you don't go we have to go to the hospital.' I said, 'Why?' And he said, 'Because it's gonna take them about a week to get my foot out of your ass!"

10. The ones that almost made it.

"Fear the Voices" and "Lying Season" were two outtakes from the Dirt sessions that didn't make it onto the final album. They were later included in the 1999 Music Bank box set and "Fear the Voices" was released as a single to promote it.

See Dirt in the 30 Best Grunge Albums of All Time