 A landmark event during Mendelssohn 's Leipzig years was the premiere of his oratorio St. Paul , given at the Lower Rhenish Festival in Düsseldorf in 1836 , shortly after the death of the composer 's father , which much affected him ; Felix wrote that he would " never cease to endeavour to gain his approval [ ... ] although I can no longer enjoy it " . St. Paul seemed to many of Mendelssohn 's contemporaries to be his finest work , and sealed his European reputation . 
