The failure of his first concert tour, a badly planned venture to Hamburg in 1799, caused him to ask Duke Karl Wilhelm Ferdinand of Brunswick for financial help. A successful concert at the court impressed the duke so much that he engaged the 15-year-old Spohr as a chamber musician. In 1802, through the good offices of the duke, he became the pupil of Franz Eck and accompanied him on a concert tour which took him as far as Saint Petersburg. Eck, who completely retrained Spohr in violin technique, was a product of the Mannheim school, and Spohr became its most prominent heir. Spohr's first notable compositions, including his Violin Concerto No. 1, date from this time. After his return home, the duke granted him leave to make a concert tour of North Germany. A concert in Leipzig in December 1804 brought the influential music critic Friedrich Rochlitz "to his knees," not only because of Spohr's playing but also because of his compositions. This concert brought the young man overnight fame in the whole German-speaking world.