John Lennon's widow Yoko Ono will tell people around the world "to learn to love each other in peace" on what would have been the music legend's 70th birthday.
Fans around the world will be remembering the late Beatle at various locations including his home town of Liverpool and a shrine in Central Park, New York, his adopted home.
Ono herself will be leading a celebration in Iceland with a series of events, including a performance by the Yoko Ono Plastic Ono Band, alongside their son Sean.
Ono will also be presenting awards to figures chosen for their contribution to world peace with a biennial award - the Lennon Ono Grant for Peace - created in 2002.
It is thought that Lennon's Beatles bandmate Ringo Starr and George Harrison's widow Olivia may also attend the event.
Lennon was murdered in 1980 by Mark Chapman who is still imprisoned for the crime. He was shot dead outside his home in the Dakota building, close to Central Park in New York, which Ono still calls home.
In a message tomorrow she will say of her late husband: "He had a very painful childhood in which he hardly saw his mother or his father. But, later, he managed to turn his pain around to give the world many beautiful songs and important messages which changed our heads and the way of our lives."
Lennon's first wife Cynthia has also shared her memories of him in an interview to be broadcast tomorrow.
In an interview with Bob Harris to be broadcast on Radio 2 in a special Lennon-themed edition of his show, she said: "The one thing that really saddens me is that he's not alive to see his two sons, who are now the best of friends, who are close together."