The Free Imperial City of Nuremberg (German: Reichsstadt Nürnberg) was a free imperial city — independent city-state — within the Holy Roman Empire. After Nuremberg gained piecemeal independence from the Burgraviate of Nuremberg in the High Middle Ages and considerable territory from Bavaria in the Landshut War of Succession, it grew to become one of the largest and most important Imperial cities, the 'unofficial capital' of the Empire, particularly because Imperial Diets (Reichstage) and courts met at Nuremberg Castle. The Diets of Nuremberg were an important part of the administrative structure of the Empire.