"As Gregor Samsa awoke one morning from uneasy dreams he found himself transformed in his bed into an enormous insect."
First lines
In October 1915.
Franz Kafka's seminal novella The Metamorphosis (Die Verwandlung) is first published in Die Weißen Blätter. Kafka finishes writing The Trial this year, but it will not be published until 1925, the year after his death.
https://en.wikipedia.org/wiki/The_Metamorphosis
The Metamorphosis at PG, translated by David Wyllie:
https://gutenberg.org/ebooks/5200