The song was originally written for the Bing Crosby and Bob Hope movie Road to Morocco in 1942.
In the film, Crosby serenades the princess underneath the palace balcony. The song is reprised throughout the film to provide a musical unity.
The song has been recorded numerous times by artists such as Ella Fitzgerald, Frank Sinatra, Glenn Miller, Johnny Mathis, Mel Torme, Paul Williams, Willie Nelson and Michael Holliday.
However, the Bing Crosby version remains the best known. His version topped the Billboard charts for over 17 weeks in 1942.