The Habsburgs were the largest and most powerful royal house of the Holy Roman Empire from the Early Modern Period until the First World War. In addition to holding significant amounts of land and influence within the Holy Roman Empire, the Habsburg dynasty ruled Spain under Charles V. As the House of Habsburg expanded into western Europe, border friction began with the Kingdom of France, the lands of which extended to the west bank of the Rhine. The subsequent rivalry became a cause for several major wars, including the Italian Wars, the Thirty Years' War, the Nine Years' War, the War of Spanish Succession, the War of Austrian Succession, and the Napoleonic Wars.