• Luxembourg declares independence after four years of German occupation in World I.

  • Luxembourg joins the League of Nations.
  • Luxembourg and Belgium join in an economic union, in which both countries use Belgium's currency.

  • Luxembourg is once more occupied by German troops during World War II.

  • Luxembourg forms an economic union with Belgium and the Netherlands.

  • Luxembourg becomes a member of the North Atlantic Treaty Organizations (NATO).

  • Luxembourg becomes a founding member of the European Economic Community, which aims to integrate the economy in Europe among its member states.

  • Following the crisis of the metallurgy sector, Luxembourg enters a period of recession. 

  • Luxembourg takes part in the Maastricht Treaty creating the European Union (EU).

  • Luxembourg adopts the euro currency.

  • Luxembourg is added to a "grey list" of countries with questionable banking arrangements by G20, which is an international forum for the governments and central bank governors from 20 major economies. 

Sources:

BBC News open_in_new
Britannica open_in_new