There were quite a few of these because by the Basic Law for the Empire of 1356, each [Holy Roman Emperor]? had to hold his first diet in Nuremberg after his election. There were also a number of other diets held.
1211 elected Frederick II of Hohenstaufen emperor.
1356 Charles IV issued his 'Golden Bull' - fixing how the German emperors were elected.
Important to Protestantism (and the Turks) were the:
1522 1st Diet of Nuremberg
1524 2nd Diet of Nuremberg
1532 3rd Diet of Nuremberg