On a day in January 1912, preoccupied and pacing the bastions of Castle Duino, the wind howling and the Adriatic raging beneath him, Rilke seemed to hear a voice which called to him from the storm:
Wer, wenn ich schriee, hörte mich denn aus der Engel Ordnungen?
Who, if I cried out, would hear me - among the Angel hierarchies?
He copied these words into his notebook and from this dramatic moment his life's mission, as he saw it, truly began. The First and Second Elegies followed immediately, but the Elegy cycle was not to be completed until 1922. Rilke believed that the Elegies were his Auftrag: the work he had been given to perform in life. For ten bitter years it must have seemed that he might never complete them.

In the February of 1922, at the little Château de Muzot, in the Valais, during an amazing three weeks Rilke experienced a frenzy of achievement: he 'completed' the Elegies and then wrote the Elegie des Saltimbanques to replace the original Fifth Elegy. But in addition he began and completed the two sequences of the Sonnets to Orpheus; a total of 55 sonnets (as they now stand) which bear close relation to the Elegies. Rilke felt himself rewarded and achieved. He died soon after, on 29 December 1926.

(From an introduction to the Duino Elegies by Stephen Cohn.)