Complex sentence: In August 1989 Hungary opened its border with Austria, creating the first gap in the so-called Iron Curtain, through which several thousand East Germans quickly fled to Hungary in hopes of reaching West Germany by way of Austria.
Split into simpler sentences: In August 1989 Hungary opened its border with Austria, creating the first gap in the so-called Iron Curtain. Several thousand East Germans quickly fled to Hungary, in hopes of reaching West Germany by way of Austria.