On March 20th, 1969 John Lennon married Yoko Ono at the British Consulate Office in Gibraltar.

They spent their honeymoon in Amsterdam campaigning for an international “Bed-In” for peace. They planned another “Bed-in” in the United States, but were denied entry. The couple then went to Montreal, and during a “Bed-in” at the Queen Elizabeth Hotel recorded ‘Give Peace a Chance’. Lennon also detailed this period in The Beatles’ ‘The Ballad of John and Yoko’, recorded by Lennon and McCartney on April 14, 1969.

Source: This Day in Music