Fifty years ago today, 200,000 Soviet troops, with reinforcements from East Germany, Poland, Hungary and Bulgaria, invaded the Czechoslovak Socialist Republic, and the so-called Prague Spring came to an end.

In January of 1968, Alexander Dubček, a Slovak, was elected First Secretary of the Czechoslovak Communist Party, succeeding Antonin Novotný. The latter had been experimenting with a new economic model for a couple of years (Czechoslovakia had been continental Europe’s most highly industrialized country until overtaken by Nazi Germany in the late 1930s and was less adapted to the post-war Soviet model), and this attempt at easing the Communist system had spurred writers, such as Milan Kundera, to demand more social flexibility as well.

The Dubček government set about achieving what the new First Secretary described as “socialism with a human face,” abolishing censorship and easing travel restrictions.