The Siegfried Idyll was never intended for the public, but it was published when the Wagner's were pressed by debt. In its original form it was called the Tribschen Idyll and first performed by a fifteen-piece orchestra as a birthday gift for Cosima. For its intimacy and emotion, the Idyll is regarded as one of Wagner's greatest works, and saw many performances. This is a study of the events of the Wagner romance that prompted its composition. Its roots stretch from their earliest days and it would affect them to their last. As a consequence, much of the Wagner romance is covered here in a condensed form.

The Siegfried Idyll, one of Richard Wagner's few non-operatic works, is a symphonic poem lasting approximately twenty minutes for chamber orchestra. Wagner composed it as a birthday present to his second wife, Cosima, after the birth of their son Siegfried in 1869. It was first performed on the morning of Christmas Eve (Cosima's birthday) in 1870 by a small ensemble on the stairs of their villa at Tribschen (today part of Lucerne) in the Canton of Lucerne, Switzerland; Cosima awoke to its opening melody. Today, it is often performed by orchestras.

Its original title was Triebschen Idyll with Fidi's birdsong and the orange sunrise. "Fidi" was the pet version of the name Siegfried. It is thought that the birdsong and the sunrise refer to incidents of personal significance to the couple.

Wagner's opera Siegfried, which was not premiered until 1876, incorporates music from the Idyll. It was once thought that the Idyll simply used musical ideas intended for the opera, but it is now known that the opposite is the case. Wagner adapted melodic material for the Idyll from an unfinished chamber piece and later incorporated it into the love scene between Siegfried and Brunhilde in the opera, somewhat disrupting the melodic and motivic unity of the larger work.

The work also uses a German lullaby, whose title can be translated "Sleep, Baby, Sleep." Wagner published a detailed program for the work which describes his mother singing the boy asleep with a lullaby and then contemplating what he will be like as a young man.