From biographical not about Goethe:
Goethe first attracted public notice with the drama Götz von Berlichingen
(1773) (see Berlichingen, Götz von), a pure product of Sturm und Drang.
Still more important was the epistolary novel Die Leiden des jungen
Werthers (1774, tr. The Sorrows of Young Werther, 1957) which Goethe,
on the verge of suicide, wrote after his unrequited love for Charlotte Buff.
Werther gave him immediate fame and was widely translated. While the
writing had helped Goethe regain stability, the novel’s effect on the public
was the opposite; it encouraged morbid sensibility.

epistolary
adj.
5Fr =pistolaire < L epistolaris < epistola, EPISTLE6
1 of or suitable to letters or letter writing
2 contained in or conducted by letters
3 written in the form of a series of letters exchanged by the characters, as certain novels of the 18th cent.