Jérôme Bonaparte thus received more attention since the famous "Treaty of Westphalia" which ended the Thirty Years' War a hundred and fifty years earlier in 1648. Thanks to these efforts by King Jerome, Kassel celebrated an enormous cultural upturn. However, Jérôme's expensive habits earned him the contempt of Napoleon. His court incurred expenses comparable to Napoleon's court (which oversaw a vastly larger and more important realm), and Napoleon refused to support Jérôme financially. In 1812, Jérôme was given command of a corps in the "Grande Armée", marching towards Minsk. Insisting on travelling "in state", Napoleon reprimanded Jerome, ordering him to leave his
War of the Fifth Coalition not been able to save Prussia. The Russian and French armies met in February 1807 at the savage and indecisive Battle of Eylau, which left behind between 30,000–50,000 casualties. Napoleon regrouped his forces after the battle and continued to pursue the Russians in upcoming months. The action in Poland finally culminated on 14 June 1807, when the French mauled their Russian opponents at the Battle of Friedland. The resulting Treaty of Tilsit in July ended two years of bloodshed and left France as the dominant power on the European continent. It also severely weakened Prussia and formed a Franco-Russian axis