Complex sentence: The Nordic Council is a geo-political inter-parliamentary forum for co-operation between the Nordic countries that was established after World War II. Its first concrete result was the introduction in 1952 of a common labour market and free movement across borders without passports for the countries' citizens.
Split into simpler sentences: The Nordic Council is a geo-political, inter-parliamentary forum for co-operation between the Nordic countries. It was established following World War II and its first concrete result was the introduction in 1952 of a common labour market and free movement across borders without passports for the countries' citizens.