This contribution maps the activity of Arnošt König (1838– 1915), an oboist of German origin, primarily in Prague’s musical life at the time. During the years 1870–1913, A. König was the professor of oboe at the Prague Conservatory, and from 1876 he was an oboist at the Prague Provisional Theatre and then at the National Theatre. Reviews and articles from the period show what an exceptional musician he was, as he earned recognition even beyond Bohemia. Many mentions praising him in the press have been preserved in connection with the difficulty for performers of Dvořák’s Serenade in D Minor, op. 44, in which A. König excelled repeatedly. It can be documented at least twice from Dvořák’s extant correspondence that performances elsewhere of the Serenade were cancelled because of its difficulty. Together with the aforementioned reviews, this fact shows that in Prague Antonín Dvořák (and others) had exceptional conditions for musical performances.