 His work in Hamburg formed the basis of his pioneering work on drama, titled "Hamburgische Dramaturgie".Unfortunately, because of financial losses due to pirated editions of the "Hamburgische Dramaturgie", the Hamburg Theatre closed just three years later.In 1770, Lessing became librarian at the ducal library, now the Herzog August Library ("Herzog-August-Bibliothek", "Bibliotheca Augusta"), in Wolfenbüttel under the commission of the Duke of Brunswick.