Which fairy tale is an autobiography of Hans Christian Andersen?

"The Ugly Duckling" is a literary fairy tale by Danish poet and author Hans Christian Andersen (1805–1875). It was first published on 11 November 1843 in New Fairy Tales. First Volume. First Collection, with three other tales by Andersen in Copenhagen, Denmark to great critical acclaim.

The tale has been adapted to various media including opera, musical, and animated film. The tale is an original story by Andersen.

Andersen first conceived the story in 1842 while enjoying the beauty of nature during his stay at the country estate of Bregentved, and lavished a year's worth of attention upon it. He initially considered "The Young Swans" as the tale's title but, not wanting to spoil the element of surprise in the protagonist's transformation, discarded it for "The Ugly Duckling". He later confessed that the story was "a reflection of my own life", and, when the critic Georg Brandes questioned Andersen about whether he would write his autobiography, the poet claimed that it had already been written — "The Ugly Duckling"