Thursday marks the 31-year anniversary of the death of John Lennon.
The legendary singer-songwriter was shot and killed Dec. 8, 1980, at age 40 in New York by Mark David Chapman at the entrance to the building where he lived. His death came just three weeks after the release of his album "Double Fantasy," which marked the first album for Lennon since the birth of his son in 1975.
PHOTOS: Hollywood's Notable Deaths
Lennon was born Oct. 9, 1940, in Liverpool, England. His first band, the Quarrymen, evolved into what became the Beatles in 1960. He and fellow band member Paul McCartney would go on to form one of the most successful songwriting partnerships of the 20th century, writing most of the group's hits.
Lennon's marriage to Japanese artist Yoko Ono in 1969 played a part in the disintegration of the Beatles a decade after the band's formation. He went on to have a successful solo career, with hits including "Mother," "Give Peace a Chance" and "Imagine."
VIDEO: Remembering the Beatles' George Harrison
Here are five iconic moments from Lennon's career:
1. Beatles' First Appearance on "The Ed Sullivan Show"
The U.K. had already been enthralled with Beatlemania when the group made its U.S. debut appearance on "The Ed Sullivan Show" in 1964, performing "All My Loving," "Till There Was You," "She Loves You" and "I Want to Hold Your Hand" to an audience full of mostly screaming females. As they performed "Till There Was You," the names of the group members were superimposed over close-ups, including the famous "Sorry girls, he's married" over Lennon. The appearance marked their breakthrough to international stardom.
2. "Sgt. Peppers Lonely Hearts Club Band"
The Beatles' 1967 album was part of the group's experimental phase and spawned such singles as the title track, "Lucy in the Sky With Diamonds" and "A Day in the Life." It was named one of the "500 Greatest Albums of All Time" by Rolling Stone in 2003. The Bee Gees -- Barry, Robin and Maurice Gibb -- starred in a 1978 film musical of the same name that featured new versions of songs from the album as well as 1969's "Abbey Road." "Sgt. Pepper's Lonely Hearts Club Band" also was featured in the Beatles' "Yellow Submarine" movie.
3. "Imagine"
After embarking on his solo career, Lennon had several hits, including this one, which endures today and is a staple on TV singing competitions like "American Idol" and "The Voice." Lennon and Ono performed the song -- which in 2004 was ranked No. 3 on Rolling Stone's "500 Greatest Songs of All Time" -- together in Madison Square Garden in 1972.
4. "Happy Xmas (War Is Over)"
Lennon would became an anti-war activist, reflected in songs like "Give Peace a Chance," his first solo single, and the holiday-themed "Happy Xmas (War Is Over)," which still gets lots of play every December. To advertise the single, Lennon and Ono paid for billboards in 12 cities around the world that read in each country's native language: "WAR IS OVER -- IF YOU WANT IT." Watch the official video below.
5. Last Full Concert Performance
Lennon gave two benefit concerts in New York's Madison Square Garden in 1972 to aid patients at the Willowbrook State School mental facility. They were has last full-length concert appearances. In the clip below, he performs "Mother."
What do you remember best about John Lennon? Let us know in the comments below.
Related content: