The commonwealth was fairly serious regional power. The 17th century it almost annexed Russia, but it came to an end as it had weakened further and further until it was partitioned by three empires; Russia, Prussia, and Austria. Their sovereignty had been eliminated, however thier culture never died.
As the First World War came to a close the map of central and eastern europe changed drastically. Many smaller nations had seen a chance to break away from Foreign powers, and the US president Woodrow Wilson made special note on Polish independence in his 14 points.