History of Strasbourg remained neutral during the Thirty Years' War (1618-1648), and retained its status as a Free Imperial City. However, the city was later annexed by Louis XIV of France to extend the borders of his kingdom. Louis' advisors believed that, as long as Strasbourg remained independent, it would endanger the King's newly annexed territories in Alsace, and, that to defend these large rural lands effectively, a garrison had to be placed in towns such as Strasbourg. Indeed, the bridge over the Rhine at Strasbourg had been used repeatedly by Imperial (Holy Roman Empire) forces, and three times during the Franco-Dutch War
European institutions in Strasbourg in Brussels and Luxembourg city. The split arrangement has caused financial, environmental and practical difficulties, with the Strasbourg location usually (though not universally) being cited as the extraneous location rather than Brussels. The École nationale d'administration, founded in 1945 in Paris, was moved to Strasbourg by decree in 1991 and permanently established there in 2005 (although the headquarters had been transferred from the start, the students had to spend half of their annual curricula in either city until that date). In the course of its refocusing on European governance, it merged with the Centre d'études européennes de Strasbourg (Center for