Born on Oct. 9, 1940, Lennon had recently turned 40 when he was shot and killed by Mark David Chapman in New York City on Dec. 8, 1980.
John Lennon, seen in the lower right in this 1960s photo of The Beatles, was fatally shot on Dec. 8, 1980. (Clockwise from top left: Paul McCartney, Ringo Starr, John Lennon and George Harrison).
Here's another 1960s publicity photo of The Beatles, (L-R) Ringo Starr, John Lennon, George Harrison and Paul McCartney (seated).
Lennon (far right) is seen here on the cover of The Beatles' debut album "Please Please Me," which was released on March 22, 1963. Of the album's 14 songs, eight were written by Lennon–McCartney, and Lennon sang or shared lead vocals on songs such as "Love Me Do," "Twist and Shout" and the title track.
Lennon is seen on the far left on the cover of The Beatles' second album, "With the Beatles," released on Nov. 22, 1963.
The Beatles wave to fans after arriving at Kennedy Airport in New York City on Feb. 7, 1964.
Lennon on the set of the TV special "The Beatles" in 1964.
The year 1964 saw "Beatlemania" hit with full force, with the soundtrack to "A Hard Day's Night" coming out in June and going to No. 1 in the United States. Lennon is seen in the top row of photographs on the album's cover here.
Lennon performing with The Beatles for the television program "Tres" in Hillegom, Netherlands, on June 5, 1964.
Lennon can be seen here second from left on the cover of The Beatles' fourth studio album, "Beatles for Sale," released on Dec. 4, 1964. The joint Lennon-McCartney composition "Eight Days a Week" would become the band's seventh No. 1 single in March 1965.
The Beatles released their sixth studio album, "Rubber Soul," in early December 1965. Lennon can be seen here second from left on the album's cover.
The Beatles, including Lennon (second from left) in a promotional image for their June 1967 album "Sgt. Pepper's Lonely Hearts Club Band."
Lennon and Yoko Ono on the first day of their Bed-In for Peace at the Amsterdam Hilton Hotel on March 25, 1969.
Lennon and Yoko Ono during their Bed-In for Peace at the Amsterdam Hilton Hotel.
Lennon and Ono leave Amsterdam after their Bed-In for Peace on March 31, 1969.
Lennon, in full beard and long hair, leads The Beatles across Abbey Road in the iconic album cover for their second-to-last album, "Abbey Road," released on Sept. 26, 1969.
Lennon, top left, is seen here on the cover of The Beatles' "Let it Be," which was released on May 8, 1970, shortly after the group announced their break-up.
The cover of "John Lennon/Plastic Ono Band," Lennon's first album release after the break-up of The Beatles. It was released on Dec. 11, 1970.
"Imagine," Lennon's second solo album, was released in the United States on Sept. 9, 1971, and in the United Kingdom on Oct. 8, 1971.
An advertisement for Lennon's album "Imagine" from Billboard magazine on Sept. 18, 1971.
Lennon and host Tom Snyder from the television program "Tomorrow." The June 27, 1975, interview was the last TV interview Lennon gave before he was murdered in 1980.
The cover of Lennon's Feb. 21, 1975, album "Rock 'n' Roll," an album of oldies including covers of such songs as "Peggy Sue," "Be-Bop-A-Lula," "Stand by Me" and "Sweet Little Sixteen."
After years of fighting deportation, Lennon was granted a green card for permanent residence in the United States in 1977.
The cover of Lennon's "Double Fantasy" album with Ono. The album, which was released on Nov. 17, 1980, preceded Lennon's murder by three weeks. Following his death, it went on to become a worldwide commercial success and win the 1981 Album of the Year Grammy.
Four years after "Double Fantasy," Ono used a similar cover image, this time in color, for the Jan. 27, 1984, release of "Milk and Honey," the first posthumous release of Lennon's music. The songs on the album were recorded in the last months of Lennon's life and was the duo's projected follow-up to "Double Fantasy." After Lennon's death, the project was temporarily shelved, with Ono resuming work on it after three years.
This John Lennon statue was unveiled outside the Cavern Pub in Liverpool, England, on Jan. 16, 1997. The statue's pose is a representation of the cover of Lennon's 1975 album "Rock 'n' Roll."
In 2004, a group of scientists released a computer-generated image of how the late singer and songwriter John Lennon might have looked if he were still alive. The scientists at the University of St Andrews in Scotland used software to reproduce the natural effects of aging, taking into account changes in skin texture, hairline and hair color.
Yoko Ono, the widow of John Lennon, speaks at a news conference in Tokyo on Nov. 2, 2006, ahead of the John Lennon Super Live charity concert to raise money to build schools in Africa and Asia.
On the 30th anniversary of John Lennon's death in 2010, fans left mementos and flowers around the Imagine mosaic in the Strawberry Fields section of Central Park.
A sculpture of Lennon's face as part of the closing ceremony of the 2012 London Olympics on Aug. 12, 2012.
Another look at the Strawberry Fields memorial to Lennon in New York City's Central Park, this time on July 17, 2012.
The search for missing University of Virginia student Hannah Graham now includes the use of an aerial drone -- the first time, according to authorities, one has been used in the search for a missing person in the state.
Photos taken by scientists working for the National Oceanic and Atmospheric Administration show more than 35,000 walruses gathered, or hauled out, on a beach near the village of Point Lay, on the Chukchi Sea in northwest Alaska on Saturday.