963 AD: Count Siegfried acquires Lucilinburhuc castle, launching the historic County and Duchy of Luxembourg.
1815: Elevated to a Grand Duchy by the Congress of Vienna, held in personal union with the Dutch crown.
1839: Treaty of London confirms Luxembourg's independence and sets its modern physical borders; the personal union with the Dutch crown continued until 1890.
WWI & WWII: German occupations discredit historic neutrality; after WWII it is formally abandoned, driving full commitment to international cooperation.
Post-WWII: Founding member of NATO and the European Coal and Steel Community, and of the Benelux economic union (1958).
Late 20th Century: Shifts from steel manufacturing into one of the world's chief financial hubs and high-income nations.